In order to obtain the friction materials that have high hardness and good abrasion resistance,and can meet the requirements of low speed and large torque operation of ultrasonic motor,the glass fiber powder filled polymerbased friction materials were prepared by cold pressing and sintering.The effect of the content of glass fiber powder on the mechanical and tribological properties,and the electrical properties of polymerbased friction materials was studied.Experimental results show that the glass fiber powder can improve the hardness,elastic modulus and impact toughness of friction materials,and the friction coefficient of friction materials is obviously improved with the increase of the content of glass fiber powder.The glass fiber powder with proper content can improve the performance of ultrasonic motor and wear resistance of friction materials,with the increase of the content of glass fiber powder,the performance of ultrasonic motor of the friction material is increased first and then decreased,the wear mechanism of the material is changed from adhesive wear to severe fatigue wear.Under the experimental conditions,the best volume fraction of glass fiber powder is 30% for the polymerbased friction materials.