The present invention discloses a method for implementing a redirection service for UEs sharing a PUI in an IMS, comprising: when a UE in a PN registers at a PNM AS, the PNM AS fetching the UE Identity and establishing a corresponding relationship between the identity and the PUI; when determining to route an initial request message of a terminating call of a UE in the PN routed by an original S-CSCF to a configured UE sharing the PUI, the PNM AS adding the configured UE Identity into a redirected initial request message and sending it to the original S-CSCF which forwards the message to a redirection S-CSCF; and the redirection S-CSCF uniquely locating the configured UE according to the identity or both the identity and the PUI in the message. The present invention can redirect a session initial request to a configured UE sharing a PUI with other UEs.