Abstract: This literature presented a self-designed spherical electrode (SE) used in resistance spot welding AA5182 aluminum alloy. Researches were carried out to study the difference on the performance of the weld compared to custom flat electrode (FE) through conducting tensile shear test, electrode life test and cracking analysis. SORPAS simulation was also conducted to verify and study the mechanism which caused these discrepancies in tensile strength, electrode life and cracking prohibition. According to both experimental and simulation results, it was preferable to adopt such self-designed SE in resistance spot welding AA5182 aluminum alloy when using median frequency spot welding machine, in which the cracking risk factor (CRF) was lower (SE:0.105～0.110, FE:0.148～0.152) and related cracking was smaller and shorter. What’s more, the electrode life was worse when using FE.