Abstract：To understand the mechanism of vibration screening on bulk materials,taking vibrating screen KZX936 as a model and based on 3D discrete element method,choosing three granularity levels of particles,the motion rule of materials and screening efficiency are simulated with different vibration frequency,amplitude and vibration direction angle using EDEM software. Simulation results show that when screen surface is long enough,the frequency,amplitude and vibration direction angle have a great influence on screening efficiency at the initial time,and screening efficiency increases with the increase of frequency and amplitude.And increased amplitude is advantageous to screening. Screening efficiency does not improve significantly with the increasing frequency and amplitude on steady state of screening. Screening efficiency increases first and then decreases with reduced amplitude 2 mm. Screening efficiency reaches the maximum with vibration direction angle 45°,and then decreases with the increasing vibration direction angle continuously.

Keyword：discrete element method;vibrating screen;screening efficiency;3D discrete element method;