Abstract: In this study, Abaqus finite element analysis and the equivalent structural stress method of Fe-safe software were used to analyze and predict the fatigue life of 6 kinds of magnesium alloy joints. The results show that the Abaqus simulation shows that there is significant stress concentration at the weld toe, and the fracture location of the fatigue test is consistent with the simulation results. The S-N curves obtained from the equivalent structural stress and fatigue life calculated by Fe-safe have a high fitting degree. The average error between the life predicted by the median curve and the actual life is 13.7%, and the average error between the life predicted by the ±2 times error curve and the actual life is within 17.2%. This method simplifies the traditional analysis process and provides a reliable technical support for fatigue evaluation of magnesium alloy joints.