Because of the SSWZ330 type crossaxle universal shaft couplings processing quality problem, the service life of it is caused of greatly reduced. CATIA threedimensional (3D) modeling software was used to do 3D entity model for it, which was then introduced into the ADAMS kinematics simulation software to simulate the coupling of movement in different shaft angle between. Under the action of the inertia force on the intermediate shaft, which generated on account of the change of the output shaft load and the coupling structure imbalance mass, dynamics analysis was carried out on the shaft. The results show that when using the coupling to work, trying to use small shaft angle. If this angle is rather bigger, the amplitude of the movement and bearing of the intermediate shaft will all become large, which results in the decreasing of life. The coupling must be ensured of processing requirements, if there is imbalance mass, also the life of the coupling can be reduced.