A method and a terminal device for keeping a subscriber identity module card in a standby state, including receiving an enabling request to enable dual standby of a first subscriber identity module (SIM) card and a second SIM card in the terminal device, wherein the first SIM card is software-implemented, and wherein the second SIM card is hardware-implemented, accessing a first network for the first SIM card by invoking a third-party interface of an operating system of the terminal and using a data file associated with the first SIM card, and implementing a dual standby of the first SIM card and the second SIM card.