A method for selecting a mobility management entity, MME, comprising: receiving, by a base station, a radio resource control, RRC, connection request of user equipment; acquiring, by the base station, priority information of multiple MMEs connected to the base station; and selecting, by the base station, a serving MME for the user equipment from the multiple MMEs according to the acquired priority information when the RRC connection request does not carry MME information, or, when the RRC connection request carries MME information and an MME indicated by the MME information cannot be selected for the user equipment due to overload of the MME or a fault of an S1 link, wherein the method is characterized in that: the base station is connected to a local MME pool and a backup MME pool, the backup MME pool provides a backup for the local MME pool, and the multiple MMEs comprise MMEs in the local MME pool and MMEs in the backup MME pool; a priority of a highest-priority MME in the local MME pool is higher than a priority of a highest-priority MME in the backup MME pool; or priorities of the MMEs in the local MME pool are all higher than priorities of the MMEs in the backup MME pool; so that the base station selects the serving MME for the user equipment in the local MME pool first when an available MME exists in the local MME pool. receiving, by a base station, a radio resource control, RRC, connection request of user equipment; acquiring, by the base station, priority information of multiple MMEs connected to the base station; and selecting, by the base station, a serving MME for the user equipment from the multiple MMEs according to the acquired priority information when the RRC connection request does not carry MME information, or, when the RRC connection request carries MME information and an MME indicated by the MME information cannot be selected for the user equipment due to overload of the MME or a fault of an S1 link, wherein the method is characterized in that: the base station is connected to a local MME pool and a backup MME pool, the backup MME pool provides a backup for the local MME pool, and the multiple MMEs comprise MMEs in the local MME pool and MMEs in the backup MME pool; a priority of a highest-priority MME in the local MME pool is higher than a priority of a highest-priority MME in the backup MME pool; or priorities of the MMEs in the local MME pool are all higher than priorities of the MMEs in the backup MME pool; so that the base station selects the serving MME for the user equipment in the local MME pool first when an available MME exists in the local MME pool. the base station is connected to a local MME pool and a backup MME pool, the backup MME pool provides a backup for the local MME pool, and the multiple MMEs comprise MMEs in the local MME pool and MMEs in the backup MME pool; a priority of a highest-priority MME in the local MME pool is higher than a priority of a highest-priority MME in the backup MME pool; or priorities of the MMEs in the local MME pool are all higher than priorities of the MMEs in the backup MME pool; so that the base station selects the serving MME for the user equipment in the local MME pool first when an available MME exists in the local MME pool.