Flow performance of abrasive powder of free discharge under different powder friction conditions was researched. According to the appraisal way of powder flow performance, the evaluation indexes of flow performance were extracted. Based on the Discrete Element Method （DEM） , the model of free discharge of powder in silo was established with PFC3D software, which was used to simulate the free discharge process of grinding wheel abrasive under different powder friction conditions. According to the simulation results, the influence of variable abrasive powder friction coefficients on the flow performance was studied. The flow performance was appraised with evaluation indexes, and fluidity functions were established. When the friction coefficient was 0.4, the flow performance of abrasive powder achieved the best. With the increase of friction coefficient , the abrasive powder flow velocity decreased and the flow stability increased.