In order to solve the problem of unclear development law of ' three zones ' in steeply inclined coal seam and gas control, this paper takes the working face of 10103-2 steeply inclined C1 coal seam in Liangshuigou Coal Mine as the object, and comprehensively uses empirical formula calculation, borehole peep measurement and 3DEC numerical simulation to systematically analyze the failure characteristics of overburden rock and the development height of ' three zones ', and construct the technical system of gas comprehensive control. The results show that the thickness of the roof fracture development zone is 7 m after roadway excavation, the height of the caving zone is 10 m and the fracture zone is about 20 m after the first section of the working face is mined, and the maximum height of the caving zone is 26 m and the fracture zone is 26 ~ 53 m after the second section is mined. Based on this, a three-in-one treatment scheme of ' upper corner buried pipe + high-level borehole + ground well ' is proposed to realize accurate extraction of different sources near working face, fracture zone and mining pressure relief. This technology effectively solves the problem of gas accumulation in steeply inclined coal seams, and provides theoretical basis and engineering reference for gas control in similar outburst coal seams.