Abstract: Based on the debugging process of the indentation depth of the exposed solder joint of a car door assembly, the causes of the poor appearance of the exposed solder joint of the car door assembly were analyzed through five aspects of the man-machine material method, and a series of effective methods for treating the poor appearance of the solder joint were analyzed In summary: adjust the welding posture of the robot, control the electrode orientation of the welding gun, improve the grinding shape and grinding posture, optimize the surface oil of the raw material, change the parameters of the welding machine and set the flow range of the welding circulation water. The test shows that the comprehensive treatment regimen can effectively improve the appearance of the door's exposed welded joints, reduce the extent of user complaints, and promote vehicle sales and national brand development.