Objective: To solve the technical problems in the design and analysis of the core parts of the mold open-closing mechanism related rod. Methods: The motion and force analysis of mold open-closing mechanism with an electric eight-bar was described in detail by using the analytical method. Results： Based on the example calculation, the relationship curve between the displacement of the slider and the crank angle was obtained, and the variation law of velocity and acceleration was further deduced. Meanwhile, the theoretical clamping force, the changing trend and the characteristics of each member force in the sheet extrusion process were analyzed. Conclusion: The method solves the implemented analysis of the electric eight-bar linkage mechanism without the need for professional software, shortening the design and prototyping cycles.