This paper analyzes the output motion and dynamic force of a compound mechanism based on planar six bar mechanism, the output stroke of the mechanism is discussed, and the calculation model of the output stroke under two different conditions is established. ADAMS is used to simulate and analyze the output stroke of the crank-rocker mechanism when ABCE is the crank-rocker mechanism. The simulation results are completely consistent with the calculation results of the model. From the simulation results of the velocity and acceleration of the mechanism, it can be seen that the motion of the mechanism is stable. When the mechanism is applied to realize plastic extrusion forming of workpieces, the accuracy is greatly improved compared with common extrusion forming workpieces.