Based on the indepth analysis of the operating mechanism of traveling wave ultrasonic motor (TRUM), the equivalent circuit model of ultrasonic motor is established from three aspects of stator, contact area and rotor. Trading off the advantages and disadvantages of the existing equivalent circuit model of TRUM, considering the influence of friction coupling on the ultrasonic motor and combining with the rotor vibration equation, an innovative equivalent circuit model of the friction layer and the rotor is proposed in this paper. And the rotorside equivalent model is optimized to integrate with the stator model into a complete motor model. Based on the established model, the equivalent circuit is simulated, and the simulation results show the influence of the rotor on the electrical characteristics of the whole motor. The validity of the proposed equivalent circuit model of TRUM is verified by comparing the testament results of the ultrasonic motor with the simulation waveform. It provides the model basis for further design of driver and controller of the ultrasonic motor.