A method and mobile communication device capable of resuming operating function of a temporarily disable SIM (subscriber identity module) card are provided. The SIM card is disposed in a mobile equipment (ME), in which a code verification state of the SIM card is recorded. When the code verification state is “verification required” state, the ME records an original personal identification number (PIN)/PIN unlock key (PIN/PUK) code corresponding to the SIM card. The method includes the steps of executing a SIM card start-up procedure; determining whether the code verification state of PIN/PUK code is the same with the state stored in the ME and whether a PIN/PUK code re-read from the SIM card is the same with the original one; and determining whether the international mobile subscriber identity (IMSI) value re-read from the SIM card is the same with original one: if so, resume and re-use the SIM card.