Abstract: To analyze large deflection beams with inflection point in compliant mechanisms, a dynamic model of the compliant mechanisms with inflection point was established, and the kinetic equations were deduced based on the Lagrange equation. The curves of the angle of rotation were obtained in MATLAB software and compared with the simulation results of ADAMS software. Results show that the rotation angle of the joint at the inflection point varies significantly with the dynamic coupling between the rods. This reflects the difference between the dynamic model of the compliant mechanism with inflection point and the dynamic model of the compliant mechanism without inflection point. The dynamic model can reflect the complicated deformation and motion of the compliant mechanisms exactly.