Abstract: In order to discover the breaking process and the dynamics features of the coal and rock ploughing and planing by the plough cutters of the thin seam pl ough, based on the finite element numerical simulation analysis method, an analysis was conducted on the explicit dynamic during the coal and rock cutting process.Ac cording to the 3D stress measurement and test of the coal and rock, a coal and rock constitutive model was established based on the Drucker Prager criterion.An analy sis and test of single factor simulation was designed with the coal and rock ploughing and planing depth, the coal and rock ploughing and planing speed and the front a ngle of the plough cutter as the horizontal factor and a study was realized on the coal and rock breaking mode and the coal and rock cutting force of the plough cutter.T he study results showed that the coal cutting lump size was related to the coal and rock ploughing and planing depth and with the depth increased, the lump size would be increased.With the ploughing and planing speed increased, the variation tendency of the coal lump size was not obvious.Under the a = 30° plough cutter role of the coal and rock, the coal cutting and planing lump size was large.The coal and rock cutting load of the plough cutter would be increased with the depth increased.With the rotary speed and cutting depth increased, the load of the plough with the front angle of 30° was in a linear rising tendency.