Particles are charged owing to contact,friction and impact in the process of industrial powder material treatment.Electrostatic separation is based on the process of friction charging to achieve physical separation of different particles,and the enhancement of particle frictional electrification is the main way to improve separation efficiency.In this paper,three-dimensional model of tribocharger and geometric model of particles were established.The mechanical model of the solution is determined by studying the interaction among particles.The numerical simulation of the friction collision of powder particles in tribocharger was carried out.The particle motion velocity and the ratio of charge to mass were obtained from the motion behavior and electrification law of the powder particles in the same area.The results show that the charge effect of the particles in the three regions of tribocharger is different,the particle charge ratio in nozzle region is the smallest,electrification is strengthened by the existence of friction rod in friction rod region,and the maximum charge ratio of the particles is obtained,but particle agglomeration and electrical neutralization affect particle charging,which leads to unstable charging in the region.The charge density ratio of particles in friction rod-free region is the most stable.The motion velocity of particles in tribocharger decreases gradually and reaches the stable value in friction rod-free area,which creates favorable conditions for the high efficient separation in high voltage electrostatic field.This research provides a technical reference for the optimization of powder particle charging and friction device.