In a method for accessing a legacy wireless network, a radio access network (RAN) node in the legacy wireless network receives an access message sent by a User Equipment (UE) attempting to access the legacy wireless network. The access message includes mobility management entity (MME) information identifying an MME accessed by the UE in an evolved network. The MME information is added by the UE from a temporary identity (ID) allocated by the MME to a first P-Temporary Mobile Station Identity (P-TMSI) in the access message. The RAN node selects a corresponding Serving GPRS Support Node (SGSN) in the legacy wireless network for the UE according to the first P-TMSI in the access message.