A variable crank length device with cam slot was added to the slide mechanism for achieving the uniform motion of the slider in the working stroke. The kinematics and dynamics analysis of this mechanism was carried out by using complex vector method and dynamic statics theory. Finally, the motion module of SolidWorks was used for the Motion analysis of this mechanism, and the motion characteristics and dynamic characteristics of the mechanism were obtained. The results showed that it was feasible to achieve uniform motion of slider in variable length crank slider mechanism.