Abstract: In view of the small size of the grinding tool in the ultrasonic grinding resonance system, the design principle of the wheel amplitude transformerwas proposed. A parallel wheel spindle device of ultrasonic grinding was designed. The spindle device was composed of longitudinal vibration horn, transversal vibration parallel grinding wheel, transducer, sleeve, conductive slip ring and standard interface tool handle. The resonant characteristics of the spindle device were compared and researched byimpedance analysis experiment andamplitude measurement. With grinding speed, feed speed and grinding depth as variables, the single factor orthogonal grinding experiments of SiCp/Al composites with or without ultrasound were performed. The results showed that ultrasonic grinding has many merits than traditional grinding. Grinding force was significantly reduced. Surface roughness was also reduced. Meanwhile, the surface quality was improved. The results provide technical support for further improving the structure of the ultrasonic grinding tool holder, the grinding process andpromoting the processing effect.