Abstract: Starting with action mechanism of ultrasonic energy field, this paper compares and reviews research progress of ultrasonic -assisted TIG, ultrasonic-TIG hybrid welding and high-frequency current stimulated ultrasonic-TIG hybrid welding, and specifically analyzes advantages and disadvantages of various ultrasonic energy field assisted methods and influence of different parameters on comprehensive properties of welded joints. It is considered that ultrasonic application mode, position and frequency are the key factors affecting the effect of ultrasonic action. High-frequency current stimulated ultrasonic-TIG hybrid welding has better engineering application value because of its high efficiency of ultrasonic energy, simple equipment and no change in the original welding gun structure.