A method for authenticating a machine type communication MTC device, the method comprising: receiving an attach request comprising a group identifier and sent by an MTC device to be authenticated, wherein the group identifier is a group identifier of an MTC group where the MTC device to be authenticated is located; determining whether a first group authentication vector bound to the group identifier exists locally, wherein the first group authentication vector is an authentication vector used for authenticating MTC devices in the MTC group; and if the first group authentication vector bound to the group identifier exists, according to the first group authentication vector, authenticating the MTC device to be authenticated, and generating a system key for the MTC device to be authenticated, wherein each MTC device in the MTC group has a device characteristic, and the device characteristic is used to uniquely identify the MTC device in the MTC group; the method characterized in that the attach request further comprises a second device characteristic used for identifying the MTC device to be authenticated; after the determining that the first group authentication vector bound to the group identifier exists locally, the method further comprises: determining whether the second device characteristic is the same as a locally stored first device characteristic, wherein the first device characteristic is a device characteristic bound to both the group identifier and the first group authentication vector; and if the second device characteristic of the MTC device to be authenticated is the same as the locally stored first device characteristic, acquiring, according to the group identifier, a second group authentication vector used for authenticating the MTC devices in the MTC group; establishing a binding relationship among the group identifier, the second device characteristic, and the acquired second group authentication vector; and according to an expected response number generated by the acquired second group authentication vector and the second device characteristic, authenticating the MTC device to be authenticated, and generating a system key of the MTC device to be authenticated. receiving an attach request comprising a group identifier and sent by an MTC device to be authenticated, wherein the group identifier is a group identifier of an MTC group where the MTC device to be authenticated is located; determining whether a first group authentication vector bound to the group identifier exists locally, wherein the first group authentication vector is an authentication vector used for authenticating MTC devices in the MTC group; and if the first group authentication vector bound to the group identifier exists, according to the first group authentication vector, authenticating the MTC device to be authenticated, and generating a system key for the MTC device to be authenticated, wherein each MTC device in the MTC group has a device characteristic, and the device characteristic is used to uniquely identify the MTC device in the MTC group; the method characterized in that the attach request further comprises a second device characteristic used for identifying the MTC device to be authenticated; after the determining that the first group authentication vector bound to the group identifier exists locally, the method further comprises: determining whether the second device characteristic is the same as a locally stored first device characteristic, wherein the first device characteristic is a device characteristic bound to both the group identifier and the first group authentication vector; and if the second device characteristic of the MTC device to be authenticated is the same as the locally stored first device characteristic, acquiring, according to the group identifier, a second group authentication vector used for authenticating the MTC devices in the MTC group; establishing a binding relationship among the group identifier, the second device characteristic, and the acquired second group authentication vector; and according to an expected response number generated by the acquired second group authentication vector and the second device characteristic, authenticating the MTC device to be authenticated, and generating a system key of the MTC device to be authenticated. determining whether the second device characteristic is the same as a locally stored first device characteristic, wherein the first device characteristic is a device characteristic bound to both the group identifier and the first group authentication vector; and if the second device characteristic of the MTC device to be authenticated is the same as the locally stored first device characteristic, acquiring, according to the group identifier, a second group authentication vector used for authenticating the MTC devices in the MTC group; establishing a binding relationship among the group identifier, the second device characteristic, and the acquired second group authentication vector; and according to an expected response number generated by the acquired second group authentication vector and the second device characteristic, authenticating the MTC device to be authenticated, and generating a system key of the MTC device to be authenticated.