The invention discloses a user attachment information updating method, equipment and a system. An operation support system receives a user attachment information update request, wherein the user attachment information update request is sent by a service registration server to the operation support system according to a short message sent by a terminal and used for requesting to update attachment information; and the operation support system sends a first instruction to user information storage equipment according to the user attachment information update request, wherein the first instruction is used for triggering the user information storage equipment to send a second instruction to service node equipment attached to the terminal currently so as to enable the service node equipment to trigger the terminal to initiate reattachment without restart according to the second instruction. Through the method, the number of instructions needed in the process of user attachment information update is reduced, the bearing stress of the signaling interface between the operation support system and the service registration server is lowered, the terminal can be triggered to initiate reattachment without restart, and the terminal can recover the Internet service of user numbers without restart.