In order to accurately calculate the value and direction of the radial force and the axial force value of the external helical gear pump,a certain type of fuel pump was taken as the research object,and the PumpLinx software was used to simulate the precise value of the hydraulic torque on the driving and driven gears during the working process of the external helical gear pump,then the meshing force and hydraulic pressure on the gear were calculated,and the value and direction of the resultant force under different working conditions were obtained.The empirical formula of the radial force of driven gear and the axial force of driving gear on the pump inlet and outlet pressure difference,tooth width and tooth tip circle diameter were given by data fitting.The results show that the simulation results are consistent with those of the empirical formula.The research results provide a reference for the design and verification of a certain type of fuel pump bearing,and also provide an approximate calculation method for the force analysis of a series of pump gears.