Based on the constant differential pressure control system of a certain aeroengine afterburner fuel regulator,the dynamic mathematical model (state space form) of the constant differential pressure control equipment with executive mechanism was deduced,the transfer function was obtained.According to the model established by Simulink,the closed loop pole-zero was obtained and six parameters influencing the stability of differential pressure control system were extracted,including nozzle diameter,the restrictor′s orifice area grads of the differential pressure control valve and the differential pressure execute valve,the core area of the differential pressure control valve and the differential pressure execute valve,their influence for system stability were studied.The reasonable component test scheme was used to perform test verification,and finally the mathematical model for the constant differential pressure control device was determined,the simulation results could be used as the basis for the dynamic stability analysis and design of the constant differential pressure control device.