Abstract: In this paper,advantages of ultrasonic spot welding were introduced,in comparison with that of resistance spot welding and laser welding. And its welding equipment,welding mechanism and investigation status in the lithium-ion battery manufacturing were demonstrated.Meanwhile,the key effects on the macroscopic appearance,microstructure and mechanical properties were systematically illustrated. To obtain the sound robustness and good quality of ultrasonic spot welded joint,a real-time controller and a new tool geometry design for the sonotrode were effective methods,but numerous unsolved issues existed. In addition,some perceptions on how to further enhance the process robustness of ultrasonic spot welded joint were proposed in this paper.