1. A method for generating an executable file of a multi-instance service, comprising: corresponding a source file to communications software of a multi-Subscriber Identity Module (SIM) multi-standby terminal; receiving supported service information of a primary user identity card of the multi-SIM multi-standby terminal and supported service information of a secondary user identity card of the multi-SIM multi-standby terminal; analyzing the supported service information of the primary user identity card and the supported service information of the secondary user identity card, to obtain a multi-instance service; performing compilation for the source file corresponding to the multi-instance service to obtain a first-class object file, wherein the multi-instance service comprises N instances, and N is a natural number greater than or equal to 2; performing an object copy of the first-class object file N−1 times, to obtain N−1 new first-class object files; and performing linking to the first-class object file and the N−1 new first-class object files, to generate an executable file.