In order to study the influence of the structural parameters of the two-side-cut ladder buffer on the cushioning properties, the dynamic process of the buffer was explored by analyzing the working principle of the buffer. According to Bernoulli"s theorem, the mathematical model of the buffer was established, and the method of modifying the Reynolds number of equivalent diameter was proposed to solve the problem that the pressure loss caused by crescent shaped throttling gap was difficult to calculate accurately. Then, through the co-simulation of ADAMS and MATLAB, the buffering process of the buffer under the action of spring operating mechanism was numerically simulated,and the modeling results are verified. On this basis, the influence of different milling surface spacing and milling surface length on the cushioning properties of side cut stepped buffer was obtained by simulation. The results of this paper provide theoretical guidance for the design of two-side-cut stepped buffer.