The model of the digital hydraulic cylinder was established by AMESim software, and effects of the pitch of the valve core screw on the performances of the digital hydraulic cylinder were analyzed. The results demonstrate with the increase of the pitch of the valve core screw, the lagged value of the displacement of the hydraulic cylinder is decreased, the amplitude of displacement is increased, the dynamic and static errors of system are both decreased distinctly, and the accuracy of the digital hydraulic cylinder is enhanced.