Abstract: By combining the CAN (controller area network) bus technology, soft-switching technology, pulsed welding technology ect., a compacted, integrative and synergic controlled tandem equipment is designed.Based on analysis of the technology requirements of twin-wire welding, the novel double-closed-loop control mode is introduced in which realizes the dynamic characteristic and external characteristic suitable for double-wire welding.In order to decrease the interference between two arcs, the CAN bus technology is applied in the communication of the twin-wire welding equipment and a synergic control device is designed.Experiments show that all the electric performance meet the design requirements, and the merits of the twin-wire high-speed welding are stable welding process, little splash, perfect weld appearace, high welding speed, little thermal input and small deformation.