Abstract: By studying the coal residues in the physical simulation on coal and gas outburst and found,there are three kinds of layer crack structure usually appeared in the process of coal and gas outburst in turn: ")"type concave body, "I" type of plane body and "(" convex body.The interaction factors of the structure evolution of crack-like coal body was gotten by analysis,such as ground stress,gas pressure,the physical and mechanical properties of coal and the constraint of cylinder wall.According to the three kinds of structure of crack-like coal body,the corresponding model for mechanics of plates and shells were established respectively,and the size relationship of their damage critical value was obtained by calculating:concave body is the most,followed by flat,convex is least;The further deductions to be drawn based on the results:the outburst will become easier as the destructive and produces outstanding power decreases with the crack coal evolving.