A method for selecting a Mobility Management Entity, MME, of a terminal group, comprising: after receiving by a first MME attach request message sent by a terminal, and determining that no effective subscription data of the terminal exist in local, the MME requesting the subscription data of the terminal from a Home Subscriber Server, HSS, (201, 301); characterized in that, after determining by the HSS that an MME serving the terminal currently is not a group representative MME, taking one of the following manners to select a new MME serving the terminal currently: manner A: the HSS returning terminal group management message and the subscription data of the terminal to the MME serving the terminal currently; the MME serving the terminal currently sending context information of the terminal to the group representative MME corresponding to a group representative MME identity in the terminal group management message, and sending attach accept message including the group representative MME identity to the terminal; and the terminal taking the MME corresponding to the group representative MME identity in the attach accept message as a new MME serving the terminal currently; or manner B: the HSS sending terminal group management message to the group representative MME, and returning the subscription data of the terminal to the MME serving the terminal currently; the group representative MME acquiring context information of the terminal from the MME serving the terminal currently according to the terminal group management message, and the MME serving the terminal currently storing received subscription data and sending attach accept message including the group representative MME identity to the terminal; and the terminal taking the MME corresponding to a group representative MME identity in the attach accept message as a new MME serving the terminal currently. after receiving by a first MME attach request message sent by a terminal, and determining that no effective subscription data of the terminal exist in local, the MME requesting the subscription data of the terminal from a Home Subscriber Server, HSS, (201, 301); characterized in that, after determining by the HSS that an MME serving the terminal currently is not a group representative MME, taking one of the following manners to select a new MME serving the terminal currently: manner A: the HSS returning terminal group management message and the subscription data of the terminal to the MME serving the terminal currently; the MME serving the terminal currently sending context information of the terminal to the group representative MME corresponding to a group representative MME identity in the terminal group management message, and sending attach accept message including the group representative MME identity to the terminal; and the terminal taking the MME corresponding to the group representative MME identity in the attach accept message as a new MME serving the terminal currently; or manner B: the HSS sending terminal group management message to the group representative MME, and returning the subscription data of the terminal to the MME serving the terminal currently; the group representative MME acquiring context information of the terminal from the MME serving the terminal currently according to the terminal group management message, and the MME serving the terminal currently storing received subscription data and sending attach accept message including the group representative MME identity to the terminal; and the terminal taking the MME corresponding to a group representative MME identity in the attach accept message as a new MME serving the terminal currently. manner A: the HSS returning terminal group management message and the subscription data of the terminal to the MME serving the terminal currently; the MME serving the terminal currently sending context information of the terminal to the group representative MME corresponding to a group representative MME identity in the terminal group management message, and sending attach accept message including the group representative MME identity to the terminal; and the terminal taking the MME corresponding to the group representative MME identity in the attach accept message as a new MME serving the terminal currently; or manner B: the HSS sending terminal group management message to the group representative MME, and returning the subscription data of the terminal to the MME serving the terminal currently; the group representative MME acquiring context information of the terminal from the MME serving the terminal currently according to the terminal group management message, and the MME serving the terminal currently storing received subscription data and sending attach accept message including the group representative MME identity to the terminal; and the terminal taking the MME corresponding to a group representative MME identity in the attach accept message as a new MME serving the terminal currently.