What is claimed is:1. A method implemented by a first device, wherein the method comprises:receiving, from a second device, first playback information corresponding to first multimedia content played by the second device, wherein the first device and the second device are located in a same wireless network;displaying a first playback control card corresponding to the first multimedia content, wherein the first playback control card comprises a first control and a second control, and wherein the second control is configured to control playback of the first multimedia content;obtaining a first user input on the first control;obtaining, in response to the first user input, from a server, and based on the first playback information, the first multimedia content;playing the first multimedia content based on the first playback information;detecting that the first device is disconnected from the wireless network; anddisplaying a second playback control card corresponding to the first multimedia content played by the second device, wherein the second playback control card comprises the first control and does not comprise the second control.2. The method of claim 1, further comprising:obtaining a sliding gesture comprising sliding on a first interface on a home screen of the first device; andfurther displaying, in response to the sliding gesture, the first playback control card in the first interface.3. The method of claim 1, wherein the second control comprises at least one of a volume icon, a volume display bar, a playback icon, a playback progress display bar, a rewind icon, a fast-forward icon, or a next-episode icon.4. The method of claim 1, wherein the first playback information comprises an identifier of the first multimedia content and a playback progress of the first multimedia content.5. The method of claim 4, wherein the first playback information further comprises at least one of a source address of the first multimedia content, a playback status of the first multimedia content, a volume status of the first multimedia content, or a playback volume of the first multimedia content.6. The method of claim 1, wherein a first playback progress of the first multimedia content played by the first device is the same as a second playback progress of the first multimedia content played by the second device.7. The method of claim 1, further comprising opening, in response to the first user input an application playing the first multimedia content.8. The method of claim 2, further comprising displaying, in the first interface, a second playback control card corresponding to second multimedia content played by a third device.9. The method of claim 8, wherein the second device is associated with a first area, wherein the third device is associated with a second area, and wherein the method further comprises determining display effects of the first playback control card and the second playback control card based on a location relationship between the first device and each of the first area and the second area.10. The method of claim 9, wherein a first display location of the first playback control card in the first interface is above a second display location of the second playback control card when the first device is located in the first area.11. The method of claim 10, wherein the first device is located in the second area, wherein the second display location is above the first display location, and wherein the method further comprises displaying first prompt information indicating whether to play the first multimedia content on the third device.12. The method of claim 1, further comprising:obtaining a second user input on the second control;sending, to the second device and in response to the second user input, a playback control command; anddisplaying first prompt information indicating that a playback control has failed when the first device does not receive a response message corresponding to the playback control command.13. The method of claim 1, further comprising:receiving, from the second device, second playback information corresponding to second multimedia content played by the second device;displaying the first playback control card and a second playback control card corresponding to the second multimedia content;obtaining a second user input; andsimultaneously playing, in response to the second user input, the first multimedia content and the second multimedia content.14. The method of claim 1, further comprising:receiving, from a third device, second playback information corresponding to the first multimedia content played by the third device; anddisplaying a second playback control card corresponding to the first multimedia content played by the second device and the third device.15. The method of claim 14, wherein a first playback progress of the first multimedia content played by the third device is the same as a second playback progress of the first multimedia content played by the second device.16. The method of claim 1, wherein the first device and the second device log in to a same user account.17. The method of claim 1, wherein the wireless network is a WI-FI network.18. A first device comprising:a memory configured to store instructions; andone or more processors coupled to the memory and configured to execute the instructions to cause the first device to:receive, from a second device, playback information corresponding to multimedia content played by the second device, wherein the first device and the second device are located in a same wireless network;display a playback control card corresponding to the multimedia content, wherein the playback control card comprises a first control and a second control, and wherein the second control is configured to control playback of the multimedia content;obtain a user input on the first control;obtain, in response to the user input, from a server, and based on the playback information, the multimedia content;play the multimedia content based on the playback information;detect that the first device is disconnected from the wireless network; anddisplay a second playback control card corresponding to the first multimedia content played by the second device, wherein the second playback control card comprises the first control and does not comprise the second control.19. A computer program product comprising computer-executable instructions that are stored on a non-transitory computer-readable storage medium and that, when executed by one or more processors, cause a first device to:receive, from a second device, playback information corresponding to multimedia content played by the second device, wherein the first device and the second device are located in a same wireless network;display a playback control card corresponding to the multimedia content, wherein the playback control card comprises a first control and a second control, and wherein the second control is configured to control playback of the multimedia content;obtain a user input on the first control;obtain, in response to the user input, from a server, and based on the playback information, the multimedia content;play the multimedia content based on the playback information;detect that the first device is disconnected from the wireless network; anddisplay a second playback control card corresponding to the first multimedia content played by the second device, wherein the second playback control card comprises the first control and does not comprise the second control.20. The computer program product of claim 19, wherein the instructions further cause the first device to:receive, from the second device, second playback information corresponding to second multimedia content played by the second device;display the first playback control card and a second playback control card corresponding to the second multimedia content;obtain a second user input; andsimultaneously play, in response to the second user input, the first multimedia content and the second multimedia content.