Aiming at the problem of gas disaster prevention and control in gently inclined close-distance outburst coal seam group in southwest China, taking the upper protective layer of M23 and the 12706 working face of M27 coal seam in Zhenxing Coal Mine as the engineering background, the pressure relief effect, protection range and gas control effect of upper protective layer mining are systematically studied, which provides technical support for gas disaster prevention and control under similar geological conditions. In this paper, the research methods of theoretical analysis, numerical simulation and field investigation are combined. Based on the slip line field theory, the failure depth of the floor is calculated, the theoretical protection range is defined, the evolution law of stress and displacement of surrounding rock after mining is analyzed, and the core indexes such as gas pressure and content are measured by field drilling to verify the control effect of protective layer mining. The results show that the theoretical calculation of the maximum failure depth of the floor is 19.80 m, which can completely penetrate the interlayer rock strata of 18 m, and has effective protection conditions in the vertical direction. The effective protection range of 50 ~ 220 m and 40 ~ 110 m is delineated by numerical simulation, which is highly consistent with the theoretical calculation results. The residual gas pressure is 0.24 ~ 0.33 MPa and the residual gas content is 4.755 8 ~ 4.811 8 m3/t in the field measurement protection range, which are far lower than the critical value of " coal and gas outburst prevention and control regulations. " The research results verify the effect of pressure relief and outburst elimination of upper protective layer mining, which can provide engineering reference for gas control of close inclined coal seam group in southwest China.