Based on Japanese JATCO automatic transmission oil pump as the research object, the performance parameters in the output pressure of 0.35, 0.85, 1.5, 0.85 MPa conditions, by changing the input speed (in engine speed range), the pump output flow and input torque are measured. JATCO automatic transmission oil pump output flow rate and rotating speed were analyzed, for the relationship between the output pressure relationship between the input torque, and oil pump rotation speed and the relationship between the input torque under different pressure. The oil pump is put forward by using the theory of regression analysis for the relation between each parameter design to provide the reference for automatic transmission oil pump performance.