The ethernet technology is used in multi-arc submerged arc welding systems communicate with each other. The structure of twin-arc high-speed SAW (Submerged arc welding) equipments based on Ethernet is proposed. The welding equipment technical requirement for Ethernet is discussed. The crucial implementations of Ethernet TCP / IP in the welding equipment is presented including designs of ARM (Advanced RISC Machines)based intelligent control unit, communication program, synergistic controlling procedures and monitoring program of welding process. The results of experiment show that the synergistic controlling for welding process, arc-starting and arc-ending are achieved with the characteristics of high transmission speed, large capacity and reliability. The formation of weld seam is improved with arc stability, and the technology of twin-arc high speed arc welding is achieved.