Abstract: Impulse welding technology is more and more used in mechanical processing. A weld seam tracking method based on the oscillating arc for impulse welding process was introduced. The basic principle of the weld seam tracking is introduced. The characteristics of welding current in impulse welding process are analyzed. According to the characteristics of impulse welding process,a finite impulse response filter was designed,which effectively filters the interference of current,and the periodic variation of the welding current was obtained. The maximum welding current and the integral difference method were compared. By comparing the integral difference between the current data at both sides of the groove,the deviation and deviation direction of the welding torch were judged. A kind of fuzzy controller was designed to adjust the deviation and realize the automatic adjustment of welding torch. The results show that the automatic adjustment of welding torch can be realized with the proposed method.