Abstract: In order to ensure the rationality of the structural design for personnel airlock lifting mechanism in nuclear power plants, the dynamic characteristics of the sealing door during the opening and closing process are analyzed. This paper adopts Automatic Dynamic Analysis of Mechanical Systems(ADAMS) software to analyze the airlock dynamics and kinematic performance, including the kinematic simulation of the driving box and the dynamic simulation  of the transmission screw. The analysis indicates that the initial installation position of the driving box in the lifting mechanism is the key factor leading to the insufficiency of lifting height. By resetting the initial installation position of the driving box and revolving the velocity and runtime of the screw, the lifting height can meet the design requirement (60mm). Also, the dynamic simulation results of the screw show that the radial force imposed on the screw can be neglected, which would not cause the rupture of the screw.