The Kaiping machine is composed of individual components, and the mutual movement of these components becomes the motion law of the Kaiping machine. How to choose between the mechanisms of a Kaiping machine depends on the task to be completed by the machine and the most suitable components. The selection of the function of the driven component machine according to the function of the Kaiping machine is mainly achieved through the motion form and law of the driven component, so the selection of the motion of the driven component must be based on the motion required by the machine. For example, continuous rotation is required, and a curved handle is selected as the follower; Require a certain range of oscillation and select a joystick as the follower; Require reciprocating movement and select the slider as the driven component; Request to perform a planar motion and select the connecting rod as the driven component. According to the characteristics of the Kaiping power source, the selection of the original moving parts should be based on the characteristics of the power source, as the original moving parts are components that directly receive external power supply. For example, using a rotary electric motor drive, selecting the component (crank) that forms the rotating pair as the prime mover; Using a mobile hydraulic cylinder drive, selecting the components (sliders) that make up the mobile pair as the prime mover, and so on.