In some examples, when the second device receives a sharing request from the first device that has a history sharing record or a preset sharing negotiation with the first device, it is determined that the first device is allowed to share the SIM card information.

In some examples, the method further includes: deactivating the SIM card of the second device after the second device enters the server mode.

In order to reduce the communication abnormalities caused by simultaneously performing, based on the same SIM card information, cellular mobile communication by the first device and the second device, after the second device enters the server mode, the second device's SIM card shared with the first device can be set as the deactivated state. The SIM card of the second device can be set as the deactivated state through a deactivation operation. The deactivation operation here may include: disconnecting the power supply to the SIM card of the second device or applying a reset signal of the first level to the reset pin of the second device.

In some examples, the second device can immediately deactivate the SIM card shared with the first device after entering the server mode. In this way, the sharing of the shared SIM card needs to be realized immediately.

In other examples, after entering the server mode and receiving the sharing SIM card request information sent from the first device, the second device may read the SIM card information from the SIM card of the second device, and then deactivate the shared SIM card. In this way, when the first device has not shared the SIM card of the second device, the second device may continue to use the unshared SIM card for communication.