A method for card locking of a mobile terminal, performed by a card locking device of a Subscriber Identity Module, SIM, card for the mobile terminal, the method comprising: receiving a first International Mobile Equipment Identification Number, IMEI, from a mobile terminal; judging, according to the first IMEI, whether a binding relationship exists between the mobile terminal and the SIM card, obtaining a judgment result, and generating a random number according to the first IMEI, the judgment result being used to indicate whether the binding relationship exists between the mobile terminal and the SIM card; and returning to the mobile terminal both the random number and the judgment result indicating whether the binding relationship exists between the mobile terminal and the SIM card; when the judgment result indicates that the binding relationship does not exist between the mobile terminal and the SIM card, prohibiting the mobile terminal from initializing the SIM card; when the judgment result indicates that the binding relationship exists between the mobile terminal and the SIM card, receiving encrypted data from the mobile terminal; authenticating, according to the encrypted data, whether the mobile terminal is capable of initializing the SIM card, and obtaining, an authentication result; the authentication result being used to indicate whether the mobile terminal is capable of initializing the SIM card; and returning the authentication result indicating whether the mobile terminal is capable of initializing the SIM card to the mobile terminal; when the authentication result indicates that the mobile terminal is not capable of initializing the SIM card, prohibiting the mobile terminal from initializing the SIM card. receiving a first International Mobile Equipment Identification Number, IMEI, from a mobile terminal; judging, according to the first IMEI, whether a binding relationship exists between the mobile terminal and the SIM card, obtaining a judgment result, and generating a random number according to the first IMEI, the judgment result being used to indicate whether the binding relationship exists between the mobile terminal and the SIM card; and returning to the mobile terminal both the random number and the judgment result indicating whether the binding relationship exists between the mobile terminal and the SIM card; when the judgment result indicates that the binding relationship does not exist between the mobile terminal and the SIM card, prohibiting the mobile terminal from initializing the SIM card; when the judgment result indicates that the binding relationship exists between the mobile terminal and the SIM card, receiving encrypted data from the mobile terminal; authenticating, according to the encrypted data, whether the mobile terminal is capable of initializing the SIM card, and obtaining, an authentication result; the authentication result being used to indicate whether the mobile terminal is capable of initializing the SIM card; and returning the authentication result indicating whether the mobile terminal is capable of initializing the SIM card to the mobile terminal; when the authentication result indicates that the mobile terminal is not capable of initializing the SIM card, prohibiting the mobile terminal from initializing the SIM card.