A method for processing information given Idle-mode Signaling Reduction and related devices, the method includes: receiving an information update request that contains identification information for identifying a UE and information of a current access network where the UE is located; and processing information relating to an access network, with which the UE is registered, according to the information update request and the identification information for identifying the UE, and information of the current access network where the UE is located contained in the information update request. A Serving Gateway includes an update request receiving unit and an information processing unit; an MME, includes an update constructing unit and an update request sending unit; and an SGSN, includes a second update constructing unit and a second update request sending unit. The foregoing method and devices combine to implement information processing given Idle-mode Signaling Reduction.