A system and method for routing SIP session which can refer to converged IP messaging (CPM) are provided in the present invention, which can send the SIP session invite message to the same user's multiple devices with the same user identifier of the same user; when the multiple devices belonging to the recipient are online simultaneously, the SIP session invite message is respectively routed by the service system to multiple devices. Thereby the problem of routing the SIP session of “one number, multiple devices”, which can refer to the CPM message and CPM session invite message, is solved, and the user experience is improved.