Aiming at the problem that the erosion state of the filter cake in the backwashing filter cannot be observed directly,and the internal structure of the filter cake is difficult to describe with traditional geometry,EDEM simulation method was used to simplify the agglomeration mechanism of particles in filter cake.The shape of filtered material was simplified to spherical particles.The flexible surface of coal-fine sandstone material was used as the model of filter cake layer.High pressure water droplets scouring at different impact velocities and angles was carried out to simulate the peeling of filter cake and the surface morphology of filter cake at different impact angles was analyzed.The results show that the mass loss of filter cake and the number of broken bonds increase with the increase of impact velocity,and increase first and then decrease with the increase of impact angle,and reaches a peak value near the impact angle of 30︒,which corresponds to the more number of cracks on the surface topography of filter cake.The simulation method is used to simulate the backwashing dynamic erosion process of filter cake with given actual parameters,and the optimum impact angle of peeling filter cake layer is obtained,which can accelerate the speed of cake separation from filter core,reduce the development cost of the backwashing filter and shorten the design cycle.