The present disclosure provides a session management method, a mobility management functional entity and a session management functional entity. The session management method includes: judging, by a mobility management functional entity, whether a UE has moved out of an allowed area; when the UE has moved out of the allowed area, determining, by the mobility management functional entity, a management message for a session of the UE; and transmitting, by the mobility management functional entity, the management message to a session management functional entity for serving the UE. The management message is adopted to trigger the session management functional entity to manage the session of the UE.