Abstract: To study the mechanism of coal rib spalling, the factors affecting the rib spalling are divided into internal factors and external factors, based on Bingham viscoelastic-plastic constitutive model of roof - coal body system, the non-stable equilibrium criterion of energy is used to obtain the conditions for the occurrence of coal rib spalling, and the relationship between coal rib spalling and coal body viscosity coefficient, elastic modulus, roof stiffness and seam thickness is analyzed from the perspective of energy. The results show that the greater the coal viscosity coefficient, the more difficult the coal wall is to spall; the greater the elastic modulus of coal, the easier the coal wall is to spall; the greater the stiffness of the roof, the easier the coal wall is; the thicker the coal seam is, the easier the coal wall is. Finally, the conclusion is verified by adopting the technology of “grouting + palm rope” to prevent and control the 11050 working face of Zhaogu No.2 mine.