Service transfer method, user device and access network device

The present invention relates to a service transfer method, a user device and an access network device. The method comprises: a user device receives a public land mobile network identifier (PLMN ID) and auxiliary information corresponding to the PLMN ID sent by a 3GPP access network entity, the auxiliary information corresponding to the PLMN ID being used for the user device to perform service transfer to a wireless local area network (WLAN) which an operator corresponding to the PLMN ID allows the user device to access; the user device performs service transfer according to the PLMN ID and the auxiliary information corresponding to the PLMN ID. The present invention improves a service transfer success rate.