Low-speed and high-torque are crucial characteristics of an ultrasonic motor, and they are positively correlated with the outer diameter of the motor. A multi-objective optimization method based on stator feature parameters is proposed to improve the low-speed and high-torque characteristics without increasing the outer diameter of the motor. For demonstration, this study considers a TRUM-70HA prototype motor as the research object. The ratio between the normal amplitude and tangential velocity of the stator teeth is used as the characterization for low-speed and high-torque characteristics. The parametric stator modeling of the 70HA is conducted using the ANSYS Workbench Environment. The multi-objective adaptive optimization of stator feature parameters is conducted. A second generation optimized prototype motor named TRUM-70HB is considered, and its mechanical performance is evaluated. The experimental results show that the maximum speed of the 70HB decreases from 65 r/min to 50 r/min, a decrease of 23.1%, and the maximum stall torque rises from 1.2 N·m to 2.4 N·m, an increase of 100%. The findings help save space in the manufacture of ultrasonic motors.