A method for unlocking a mobile terminal by an operator, characterized by comprising: an operator device receiving an unlocking request from the mobile terminal, wherein the unlocking request carries unlocking identification information; the operator device determining to allow the mobile terminal to unlock according to the unlocking identification information, and querying, according to the unlocking identification information, a cryptographic key list database pre-stored in the operator device to obtain an unlocking cryptographic key; and the operator device sending the unlocking cryptographic key to the mobile terminal to ensure that the mobile terminal carries out the unlocking according to the unlocking cryptographic key; the unlocking identification information comprises: a network control password of the mobile terminal and identification information of the mobile terminal: and the operator device determining to allow the mobile terminal to unlock according to the unlocking identification information comprises: the operator device detecting whether the network control password of the mobile terminal and the identification information of the mobile terminal are legal, if both of the network control password of the mobile terminal and the identification information of the mobile terminal are legal, determining whether or not a current state of the mobile terminal allows unlocking, and if yes, determining to allow the mobile terminal to unlock; determining whether or not the current state of the mobile terminal allows unlocking comprises one of the following modes:determining whether or not service time of the mobile terminal satisfies a specified time; determining whether or not network traffic used by the mobile terminal satisfies a specified traffic value; and determining whether or not an amount of consumption of the mobile terminal satisfies a specified amount value, and the unlocking identification information further comprises a locking mode which is one of the followings: a network locking mode, a card locking mode, a terminal locking mode and a cell locking mode; and according to the unlocking identification information, querying the cryptographic key list database pre-stored in the operator device to obtain the unlocking cryptographic key comprises:the operator device, according to the identification information of the mobile terminal and the locking mode, querying the cryptographic key list database pre-stored in the operator device to obtain the unlocking cryptographic key. an operator device receiving an unlocking request from the mobile terminal, wherein the unlocking request carries unlocking identification information; the operator device determining to allow the mobile terminal to unlock according to the unlocking identification information, and querying, according to the unlocking identification information, a cryptographic key list database pre-stored in the operator device to obtain an unlocking cryptographic key; and the operator device sending the unlocking cryptographic key to the mobile terminal to ensure that the mobile terminal carries out the unlocking according to the unlocking cryptographic key; the unlocking identification information comprises: a network control password of the mobile terminal and identification information of the mobile terminal: and the operator device determining to allow the mobile terminal to unlock according to the unlocking identification information comprises: the operator device detecting whether the network control password of the mobile terminal and the identification information of the mobile terminal are legal, if both of the network control password of the mobile terminal and the identification information of the mobile terminal are legal, determining whether or not a current state of the mobile terminal allows unlocking, and if yes, determining to allow the mobile terminal to unlock; determining whether or not the current state of the mobile terminal allows unlocking comprises one of the following modes:determining whether or not service time of the mobile terminal satisfies a specified time; determining whether or not network traffic used by the mobile terminal satisfies a specified traffic value; and determining whether or not an amount of consumption of the mobile terminal satisfies a specified amount value, and the unlocking identification information further comprises a locking mode which is one of the followings: a network locking mode, a card locking mode, a terminal locking mode and a cell locking mode; and according to the unlocking identification information, querying the cryptographic key list database pre-stored in the operator device to obtain the unlocking cryptographic key comprises:the operator device, according to the identification information of the mobile terminal and the locking mode, querying the cryptographic key list database pre-stored in the operator device to obtain the unlocking cryptographic key.