In industrial Ethernet, large volume of data is transferred by UDP, but the traditional UDP is non-linked and don’t deal with the dropout packet and delay. A new protocol Tolerate Error Reliable UDP (TERUDP) is put forward based on traditional UDP. It re-defines packet loss. Moreover, the concepts of valid delay and invalid delay are introduced, according to which it determines whether to retransmit missing packet and the delivery time of retransmission application. The paper suggests detecting network congestion according to virtual receiving rate and actual receiving rate and packet loss rate and then responding to it. Simulation results show that TERUDP without changing the efficiency of traditional UDP improves the reliability, reduces the network packet loss rate and delay, and increases the network data transmission efficiency.