What is claimed is:1. A positioning cycle adjustment method, comprising:obtaining, by a mobile device, N groups of environment record information in a current environment, each environment record information of the N groups of environment record information comprising an RSS of an environment signal, a receiving time of the environment signal, and an information source identifier of the environment signal in the current environment, and N being an integer greater than or equal to 2;determining, by the mobile device, a location change rate value of the mobile device based on the N groups of environment record information, the location change rate value reflecting a location change distance of the mobile device per unit of time, and wherein determining the location change rate value of the mobile device comprises:calculating, by using a quantity of information sources that generate the environment signal as a dimension of the environment record information and using the environment record information as a location point of the mobile device, a distance between location points of the mobile device that are corresponding to the N groups of environment record information, wherein calculating the distance between the location points of the mobile device comprises:in response to N being greater than 2, calculating a first distance between location points of the mobile device that are corresponding to environment record information of the environment signal with an earliest receiving time and environment record information of the environment signal with a latest receiving time in the N groups of environment record information, and using the first distance as the distance between the location points of the mobile device that are corresponding to the N groups of environment record information; anddividing the distance between the location points of the mobile device by a receiving time difference between an environment signal with the earliest receiving time and an environment signal with the latest receiving time in the N groups of environment record information, to obtain the location change rate value of the mobile device; andadjusting, by the mobile device, a positioning cycle of the mobile device based on the location change rate value.2. The method according to claim 1, wherein the environment signal comprises at least one of the following signals that are detected by the mobile device:a cellular signal, a Wireless Fidelity (WiFi) signal, a Bluetooth signal, an optical signal, or a geomagnetic field signal.3. The method according to claim 1, wherein before calculating the distance between the location points of the mobile device that are corresponding to the N groups of environment record information, the method further comprises:in response to first environment record information comprising an RSS of an environment signal generated by a first information source, and second environment record information not comprising the RSS of the environment signal generated by the first information source, assigning, in the second environment record information, a predetermined value to the RSS of the environment signal generated by the first information source,the first environment record information and the second environment record information being two groups of environment record information that are used to calculate the distance in the N groups of environment record information.4. The method according to claim 1, wherein the distance comprises any one of the following distances:a Euclidean distance, a standardized Euclidean distance, a Manhattan distance, or a Chebyshev distance.5. The method according to claim 1, wherein determining the location change rate value of the mobile device comprises:extracting features of the N groups of environment record information, the feature being a value that can be identified by a training model, and the training model being used to obtain, based on an input feature of environment record information, a location change rate value corresponding to the input feature of the environment record information; andinputting the features of the N groups of environment record information into the training model, to obtain a location change rate value that is output by the training model, and using the location change rate value that is output by the training model as the location change rate value of the mobile device.6. The method according to claim 1, wherein adjusting the positioning cycle of the mobile device comprises:adjusting the positioning cycle of the mobile device to a positioning cycle corresponding to the location change rate value in a preset correspondence,the preset correspondence comprising at least one location change rate value and a positioning cycle that is in a one-to-one correspondence with the at least one location change rate value.7. The method according to claim 1, wherein adjusting the positioning cycle of the mobile device comprises:determining whether a difference between the location change rate value and a previous location change rate value of the mobile device is greater than or equal to a preset threshold; andadjusting, by the mobile device, the positioning cycle of the mobile device based on the location change rate value in response to the difference being greater than or equal to the preset threshold.8. A positioning cycle adjustment method, comprising:obtaining, by a mobile device, N groups of environment record information in a current environment, each environment record information of the N groups of environment record information comprising an RSS of an environment signal, a receiving time of the environment signal, and an information source identifier of the environment signal in the current environment, and N being an integer greater than or equal to 2;determining, by the mobile device, a location change rate value of the mobile device based on obtained the N groups of environment record information, the location change rate value reflecting a location change distance of the mobile device per unit of time, and wherein determining the location change rate value of the mobile device comprises:calculating, by using a quantity of information sources that generate the environment signal as a dimension of the environment record information and using the environment record information as a location point of the mobile device, a distance between location points of the mobile device that are corresponding to the N groups of environment record information, wherein calculating the distance between the location points of the mobile device that are corresponding to the N groups of environment record information comprises:in response to N being greater than 2, separately calculating a first distance between location points of the mobile device that are corresponding to two groups of environment record information of two environment signals with adjacent receiving time in the N groups of environment record information, and averaging obtained Ni first distances to obtain the distance between the location points of the mobile device that are corresponding to the N groups of environment record information; andadjusting, by the mobile device, a positioning cycle of the mobile device based on the location change rate value.9. A mobile device, comprising:a non-transitory memory comprising instructions; anda processor coupled to the non-transitory memory, the instructions being executed by the processor to cause the mobile device to be configured to:obtain N groups of environment record information in a current environment, wherein each environment record information of the N groups of environment record information comprises an RSS of an environment signal, a receiving time of the environment signal, and an information source identifier of the environment signal in the current environment, and wherein N is an integer greater than or equal to 2;determine a location change rate value of the mobile device based on obtained N groups of environment record information, wherein the location change rate value reflects a location change distance of the mobile device per unit of time, and wherein determining the location change rate value of the mobile device comprises:calculating, by using a quantity of information sources that generate the environment signal as a dimension of the environment record information and using the environment record information as a location point of the mobile device, a distance between location points of the mobile device that are corresponding to the N groups of environment record information, wherein calculating the distance between the location points of the mobile device comprises:in response to N being greater than 2, calculating a first distance between location points of the mobile device that are corresponding to environment record information of the environment signal with an earliest receiving time and environment record information of the environment signal with a latest receiving time in the N groups of environment record information, and using the first distance as the distance between the location points of the mobile device that are corresponding to the N groups of environment record information; anddividing the distance between the location points of the mobile device by a receiving time difference between an environment signal with the earliest receiving time and an environment signal with the latest receiving time in the N groups of environment record information, to obtain the location change rate value of the mobile device; andadjust a positioning cycle of the mobile device based on the location change rate value.10. The mobile device of claim 9, wherein the environment signal comprises at least one of the following signals that are detected by the mobile device:a cellular signal, a WiFi signal, a Bluetooth signal, an optical signal, or a geomagnetic field signal.11. The mobile device of claim 9, wherein the instructions further cause the mobile device to:in response to first environment record information comprising an RSS of an environment signal generated by a first information source, and second environment record information not comprising the RSS of the environment signal generated by the first information source, assign, in the second environment record information, a predetermined value to the RSS of the environment signal generated by the first information source, wherein:the first environment record information and the second environment record information are two groups of environment record information that are used to calculate the distance in the N groups of environment record information.12. The mobile device of claim 9, wherein the distance comprises any one of the following distances:a Euclidean distance, a standardized Euclidean distance, a Manhattan distance, or a Chebyshev distance.13. The mobile device of claim 9, wherein the instructions further cause the mobile device to:extract features of the N groups of environment record information, wherein the feature is a value that can be identified by a training model, and the training model is used to obtain, based on an input feature of environment record information, a location change rate value corresponding to the input feature of the environment record information; andinput the features of the N groups of environment record information into the training model, to obtain a location change rate value that is output by the training model, and using the location change rate value that is output by the training model as the location change rate value of the mobile device.14. The mobile device of claim 9, wherein the instructions further cause the mobile device to:adjust the positioning cycle of the mobile device to a positioning cycle corresponding to the location change rate value in a preset correspondence, wherein:the preset correspondence comprises at least one location change rate value and a positioning cycle that is in a one-to-one correspondence with the at least one location change rate value.15. The mobile device of claim 9, wherein the instructions further cause the mobile device to:determine whether a difference between the location change rate value and a previous location change rate value of the mobile device is greater than or equal to a preset threshold; andadjust, by the mobile device, the positioning cycle of the mobile device based on the location change rate value in response to the difference is greater than or equal to the preset threshold.