Embodiments of the present invention provide a packet loss processing method, a destination network node device and a mobile transmission network system. The method includes: receiving, by a destination network node device, data sent through at least two transmission quality measurement protocol links by a source network node device, where service priorities of the at least two transmission quality measurement protocol links are different; and determining a reason for occurrence of packet loss according to packet loss ratios and the service priorities on the at least two transmission quality measurement protocol links when it is detected that packet loss occurs on the at least two transmission quality measurement protocol links. Technical solutions of the embodiments of the present invention for distinguishing bit error packet loss and congestion packet loss are high in efficiency.