Resistance spot welding is the most widely used welding process in the assembly process of automobile body. The efficiency of the spot welding process depends on the life of the electrode head, and the water cooling effect of the electrode head is directly related to the life of the electrode head under continuous working conditions. Related. Around the problem of the cooling effect of the cooling water in the resistance spot welding process, the numerical simulation method is used to truly simulate the fluid flow in the electrode head cooling cavity, and the problems of the cooling water effect and the convective heat transfer of the electrode head are carried out. A detailed analysis has laid the foundation for further improving the water cooling effect of the electrode tip and extending the life of the electrode tip.