In order to improve control performance of multi-degree-of-freedom( M-DOF) ultrasonic motor,modal characteristics and output characteristics of the motor should be tested accurately. A measurement and control platform for torsional-longitudinal 2-DOF motor was put forward,and testing principle and method were also illustrated. By testing the amplitude of the stator surface and the velocity of the rotor,the validity of smooth impact drive method( SIDM) was proved.