The present invention relates to the technical field of wireless communications. Disclosed are a gateway selection method and device, which are used to solve the problem of how to select a packet data gateway (PGW) for a mobile relay node (RN). In the present invention, a mobility management entity (MME) receives an initial UE message carrying identity indication information of the RN and sent by a donor base station DeNB; acquiring subscription data of the RN from a home subscriber server (HSS); the MME determining, according to the identity indication information and/or subscription data of the RN, whether the RN is a mobile RN, and if the determination is yes, selecting a PGW located in a core network as the PGW of the RN. By means of the present invention, the problem of how to select the PGW for the mobile RN is solved.