Abstract: A method to maintain Network Address Translation (NAT) binding is provided in the present invention, comprising a mobile terminal proactively initiating a connection request for establishing a link to a computing device via a wireless network, an edge NAT router connected to the wireless network, and other routers; the edge NAT router mapping a source address of a data packet from the mobile terminal to the source address of the edge NAT router, and mapping a destination address of the data packet from the computing device to the destination address of the mobile terminal, and maintaining the two address mapping relationships for a first time interval; the computing device sending a heartbeat packet to the mobile terminal according to a second time interval smaller than the first time interval, so a Time To Live (TTL) set value progressively decreases to 0 as the heartbeat packet reaches the edge NAT router, wherein the heartbeat packet sent by the computing device is used to maintain the mapping relationship