Abstract: The application of power ultrasonic is prospective in arc welding as it is energy-saving, environment-friendly,efficient and the improvement of the welding quality. The recent research progress of application of power ultrasonic in arc welding was summarized. Also, the ultrasonic effects and the characteristics of power ultrasonic assistance in various welding methods were discussed. In addition, the research directions of ultrasonic technology in arc welding were prospected. It provides some valuable references for scholars who study the fundamental research and engineering applications of ultrasonic technology in arc welding process.