According to the working mechanism of M4 electrohydraulic proportional multiway valve, the mathematical model of its pilot valve electrohydraulic proportional relief valve was established and simulated in Simulink platform. M4 multiway valve of pilot proportional relief valve has good step response characteristic. The model of working system of M4 electrohydraulic proportional multiway valve was established with using of power bond graph method. The dynamic characteristics of the working circuit were analyzed. The analysis results show that M4 multiway valve working system has quite good stability and good dynamic response, which provide the basis for the choice of application of proportional multiway valve in working system.