Cup wall forming mechanisms are the major mechanisms of automatic paper cup forming machine to complete a paper cup. To ensure reliable and forming quality of paper cup wall, virtual prototype technology was applied. The three-dimensional solid model of cup wall forming mechanism of JBZ-B type automatic paper cup forming machine was established and the kinetic simulation was carried out. Its motion characteristics under different working conditions as well as effect on the shaping quality of paper cup were analyzed. The purpose was to provide reference for product quality control.