The authors has expounded the top coal crushing mechanism and reasonable determination of caving coal height in roof caving workface,which helps to determine the feasibility of roof caving and complete mining according to the thickness of top coal and the degree of softness and hardness.

In the light of the fragmentized coal body in 2315 comprehensive mechanical coal mining face of Chengzhuang Coal Mine, this paper applies the grouting solidifying technology with Malisan N to solve successfully the difficulties existing in the ceiling management in the stoping process.

In the light of the hidden dangers existing in the back production of comprehensive mechanized coal mining face, this paper advances the scheme of reinforcing the fragmentized coal body around the geological structure to assure the smooth completion of the back production of coal mining face.