It should be noted that the foregoing embodiment is described by using an example in which the MODEM 1 and the MODEM 2 respectively correspond to different SIM cards. However, in practice, a case in which one SIM card is used by a plurality of users is also applicable to a scenario of this embodiment of the present invention. For example, a user 1 and a user 2 using a SIM card may suffer service resource preemption mentioned above. Therefore, according to the corresponding solution, that the two MODEMs concurrently perform services, that is, perform at the same time, can be changed to that the two MODEMs cannot perform services at the same time. In this way, service resource preemption is implemented. Alternatively, reverse switching is implemented. Therefore, the foregoing embodiment is applicable to any application scenario in which that the two MODEMs concurrently perform services is changed to that the two MODEMs preempt service resources, to implement service execution by one of the MODEMs or reverse switching. For example, the application scenario includes switching between SGLTE (simultaneous GSM and LTE) and GSM or an LTE single mode, or switching between SVD (simultaneous voice and data) and a CDMA single mode. The embodiments of this application may also be applied to a multi-SIM terminal including a physical SIM and a virtual SIM.