Abstract: Aiming at the problem of coal and gas outburst happening in the process of coal roadway excavation, the theoretical analysis of the width range of the pressure relief zone of the coal body in the coal roadway face is obtained. The pressure zone width is affected by many factors such as coal seam interface friction factor, coal body tensile strength, coal seam thickness, coal rock bulk density, lateral pressure coefficient and coal seam mining depth. The grey correlation analysis method is used to determine the coal side pressure coefficient as the main control factor of the unloading zone width, and the correctness of the numerical analysis of the unloading zone width is verified. It is put forward that external load should be applied on coal roadway driving face to destroy the integrity of coal body, increase the lateral pressure coefficient of coal body so as to increase the width of pressure relief zone, and realize the increase of coal body thickness to resist gas outburst and reduce the occurrence of outburst accidents. The research conclusion provides theoretical guidance for the study of coal and gas outburst in the driving face of coal roadway.