The present invention discloses an application takeover method and system, a mobile terminal, and a server. The application takeover method includes: receiving, by a server, an application takeover instruction sent by a first terminal, where the application takeover instruction includes an identifier of a second terminal and information about an application, of the first terminal, to be taken over, the application takeover instruction is used to make the application of the first terminal be taken over by the second terminal, and the application takeover instruction is generated by the first terminal based on sending an application takeover request to the second terminal and receiving a takeover accept response returned by the second terminal; and establishing, by the server, a takeover correspondence between the first terminal and the second terminal according to the application takeover instruction.