To study the influence of blanket deformation on printing pressure in the printing process, and the problem that printing pressure is also undetermined. Method based on Hertz theory, we analyze the factors affecting printing pressure, build a cylinder test stand based on offset printing machine, and establish a rigid-flexible coupling dynamics model with blanket as a flexible body and other parts as rigid bodies based on rigid-flexible coupling theory, which can more accurately reflect the dynamic characteristics of the cylinder test stand and the dynamic excitation between printing cylinders.