Abstract: Abaqus finite element analysis and the equivalent structural stress method of Fe-safe software were used to analyze and predict the fatigue life of six kinds of magnesium alloy joints. The results show that the Abaqus simulation demonstrates 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 the fatigue life calculated by Fe-safe have a high fitting degree. For butt joint, cruciform non-load-carrying joint, T-joint, cruciform load-carrying joint, longitudinal cruciform joint, and lateral connection joint, 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.