With the implementation of intelligent and connected vehicle, the application of semi-active suspension has become more extensive. In this paper, the effect of semi-active suspension on vehicle durability is studied. Firstly, a semi-active suspension vibration model is established based on the actual skyhook damping control model, and it is applied to a vehicle-suspension seven degrees of freedom(7DOF) model. Next, the suspension performance evaluation index is determined based on this 7DOF model, and the optimal skyhook damping control coefficient was calibrated. Then, the fatigue damage analysis was carried out based on a typical sedan finite element model using the inertia release method followed by the quasi-static superposition method, with the four-channel vertical force output from the suspension model as stimulation. The fatigue damage key locations of the vehicle body were determined, and the fatigue damage values were compared when using a semi-active suspension and a passive suspension, and it was found that the fatigue life of the former was optimized to a greater extent.