Enameled wire welding machine is a hot pressure welding technology,and it is mainly used to weld the products like stator and steering gear etc. It is a welding method that can heat the terminal and wire with insulation layer,then pressure welding them together,making them connected and conduct electricity. With the help of the internal engineering defect in the production site,and through the analysis of the welding machine’s theory,optimize the welding proposals based on the four stages of original prepressing,welding,pressure maintaining and ceasing,adding the preheating stage into it. Meanwhile,compare it with the benchmark’s level,analyze and determine the main control parameters during the welding process. The optimal control parameters are determined by carrying out the DOE test. Verification in small batch production,implementation of control methods,and ultimately reduce the internal engineering badness rate from 1.29% to 0,achieving the real zero defect.