The invention discloses a method for communicating an application processor and a modem. A physical link is provided between the application processor and the modem and corresponds to multiple virtual channels. The modem is embedded in a user equipment, and the user equipment is adapted for multiple user identification module cards. The method comprises: establishing, by the application processor, a relation of combining virtual channels to the user identification module card for receiving the service requests when service requests are sent to at least a user identification module card of the user equipment; and transferring the service requests to the user identification module card through the virtual channels which have the relation of combining to the user identification module card. The virtual channels which have the relation of combining to the user identification module card transfer the service requests so as to combine each user identification module card in a multi-card multi-standby mobile phone to a corresponding channel, avoiding the situation that when the intelligent phone transfers the service request, it is uncertain which channel is identified to transfer the service request and which user identification module card receives the transferred service request.