The main research is the dynamics characteristic of the shock excitation part of electro hydraulic control harmonic aging stress elimination devices. Use the system dynamics knowledge to set up a dynamics model of the shock excitation part. Analyze the transfer function of system and then use MATLAB to draw graphics under the condition of different parameters. Through the simulation graphic's analysis, we can obtain the influence of various parameters on system model, so as to provide a reference for the system optimization. MATLAB is abbreviation of Matrix Laboratory, which is used for algorithm development, data visualization, data analysis and numerical calculation of high-level technical computing language and interactive environment. It is useful for us in modeling and simulation.