a packet data session release method for ultra mobile broadband access network is disclosed , and which includes : s 402 , when releasing the packet data session , an access gateway sends a proxy mobile ip registration revocation message to the data attachment point of the ultra mobile broadband access network and the evolved base station which has one reverse proxy mobile ip tunnel to the access gateway , respectively ; s 404 , after receiving the proxy mobile ip registration revocation message , the data attachment point and the evolved base station which has one reverse proxy mobile ip tunnel to the access gateway , delete their proxy mobile ip tunnels between them and the access gateway , respectively , and send a proxy mobile ip revocation ack message to the access gateway , respectively , so as to confirm the reception of the registration request messages ; and s 406 , the data attachment point notifies the session reference network controller that the packet data session has been released , via sending a ip tunnel notification message to the session reference network controller .