In order to improve design efficiency, combine the software of ADAMS and Simulink to do simulation study for dynamoelectric automatic mechanism system. With the automatic mechanism of certain type gas-operated weapon as the research object, the dynamoelectric automatic mechanism system was established, in which the servo motor was used as the power, the crank-slider mechanism as the transmission mechanism, and the control system used the double close-cycle control with electric current and velocity as the controlling parameters. The 3-D model, dynamics model and the control scheme were set up on Solidworks, ADAMS and Matlab/Simulink respectively, and the co-simulation were completed by the ADAMS/Control interface module. The simulation results demonstrated that the system had good path tracking ability to the input signal, and showed that the established dynamics model and electric controlling model were accurate and could provide reliable basis for the design of dynamoelectric automatic mechanism system.