The performance of the actuator directly affects the closed loop comprehensive characteristics and flight safety of the UAV system.In view of the current situation that the digital actuator does not provide the bandwidth technical index and the actual demand of control law design,the principle and data processing method of bandwidth by using correlation measurement method are introduced, the design idea and scheme of using the UAV’s own equipment to integrate the actuator bandwidth test system is put forward, and the test process and precautions are summed up.Finally, the actuator is taken as an example,the frequency characteristic data obtained by the test is compared with the two standard order mathematical model of the actuator.It is found that the time delay of the measurement system leads to the phase error, and the bandwidth correction scheme of the actuator bandwidth is given. The approximate two standard order mathematical model of the actuator which is most consistent with the measured results is sought,and The bandwidth and damping ratio of the rudder under no load and load condition are obtained, It provides technical support for actuator selection and control law design optimization.