Abstract: With reference to the evaluation method of electrode life in 《AWS/SAED8.9M:2002》 of the American Welding Society, the life of copper electrode during resistance spot welding of 5182-H111 aluminum alloy material commonly used in 1.2mm body was studied, and the key factor affecting the life of copper electrode was revealed to be the interface reaction between copper and aluminum. The relationship between resistance of copper electrode material to high temperature softening - softening channel during welding - life of copper electrode is established. The effects of the type and composition of copper electrode and the surface state of aluminum alloy on the electrode life were studied. The results show that when 5182-H111 rolled sheet is welded under the same welding process parameters, the corresponding life sequence of electrodes with different copper electrode types and components is as follows: C15760 > C18200 > C18150 > C18140 > C15715, The corresponding electrode life of C18140 copper electrode is 43 points, C18150 copper electrode life is 48 points, C18200 copper electrode life is 61 points, C15715 copper electrode life is 38 points, and C15760 copper electrode life is 83 points. C15760 copper electrode was used for testing. Under the optimal process parameters corresponding to their respective surface states, the electrode life sequence corresponding to different aluminum alloy surface states was as follows: Passivated plate > clean plate > rolled plate, the electrode life of rolled aluminum alloy plate is 83 points, the electrode life of cleaned aluminum alloy plate is 260 points, and the electrode life of passivated aluminum alloy plate is 380 points.