The dynamic features of the jet pipe servo valve are inaccurate when its mathematical relationship is deduced according to experience and mathematical derivation. Aiming at the jet pipe electro hydraulic servo valve armature feedback component stiffness, torque motor electromagnetic torque and the flow field of the jet pipe receiver, finite element analysis tool was used to get the physical significance data, then MATLAB was used to fit the mathematical relationship among the data. The multifield simulation was made. Then the frequency response and step response relationship between input and output of the whole valve were gotten which could accurately reflect the actual valve work state. The simulation results coincide with the actual work process and the influences of materials and key design dimensions are considered in the finite element analysis. It provides a new idea for the jet pipe servo valve design.