Abstract: In order to meet the requirements of EVA (Extra-Vehicular-Activity)and RVD (RendzVous and Docking) of manned space vehicles, it is necessary to develop a hatch mechanism with high reliability and good seal performance which can be operated by both electromotion and manual. Based on analyses of the hatch characteristics of manned space vehicles, a new design project for the electric latching mechanism of the hatch is put forward. The switch mechanism used to transfer the modes of electric/manual operation is designed, which make the manual mode separate from electromotion. By software Pro/E, the models of hatch mechanism parts are constructed and assembled. Kinematic simulation on the hatch mechanism is carried out with software ADAMS. The simulation results show that the new electric/manual hatch can realize its motion correctly and has the advantage of simple structure, little resistance force and high transmission efficiency.