Abstract: The high-efficiency ultrafine powder crushing device was designed based on ultrasonic vibration principles. The crushing process of materials by high frequency impact of horn was simulated by the analysis software of extended distinct element method (EMEM). A comparative experiment was designed to analyze the effect of ultrasonic frequency, particle size (diameter), and particle material on the crushing efficiency. The results show that, with the increase of ultrasonic frequency, the crushing efficiency first increases and then tends to stable. Considering the system stability, 38 kHz is selected as the optimal ultrasonic vibration frequency. The device shows a good crushing effect on the particles in the size of 200~500μm. The device has a good crushing effect on the natural and synthetic materials with high strength and high hardness. As the material hardness decreases, the crushing effect of device gets better. It is found that the crushing device is particularly suitable for the materials in micro-defects and micro-cracks. The reliability of simulation is confirmed by the comparative experiment.