A multimedia session call control method and an Application Server (AS). The multimedia session call control method includes these steps: a multi-UE party performs a multimedia session with a peer under control of an AS; a master UE of the multi-UE party establishes a session with a third party under control of the AS; and the AS binds a call leg between a slave UE of the multi-UE party and the AS to the session established with the third party.