To study the characteristics of hydraulic bumper, the mathematical model of hydraulic bumper was established according to Bernoulli. The calculation model was set up by the graphical simulation tools of the Simulink. Then the structure parameters of the model were calculated, and the influence of parameters of the stream bore to the performance of the buffer was analyzed. The results show that the deeper groover is, or the shorter buffer is, the better buffering effect is. It provides a parameterized design tools of the hydraulic bumper, and convenient for design of different working conditions. The model has a certain engineering significance.