The stiffness of the plate shearing machine tool refers to the ability of the machine tool to resist deformation under the action of external forces. The greater the stiffness of the machine tool, the higher the dynamic accuracy. The stiffness of machine tool includes the stiffness of machine tool components themselves and the touch stiffness between the components. The stiffness of the machine tool component itself mainly depends on the data nature of the component itself, the shape of the section, size and so on. The touch stiffness between components is not only related to the touch data, the geometric size and hardness of the touch surface, but also related to the surface roughness, geometric accuracy, processing methods, touch surface media, pre-pressure and other factors of the touch surface.