Abstract: With the development of coal mining in Yima mining area, the mining depth continues to extend downward, and coal mining activities in areas with complex structures are inevitable. In order to improve production efficiency, large-scale equipment is gradually being adopted by coal mines. At the same time, the cross-sectional area of the roadway is also expanding to meet the needs of the use of large equipment and ventilation. The large cross-section roadway reduces the stability of the surrounding rock and brings another huge challenge to the support of the roadway. The roadway of 21170 mining face in Changcun Coal Mine is a typical large-section supporting roadway with serious deformation and heavy repair work, which has seriously affected the safe and efficient production of the working face. This article is based on the engineering geological conditions of roadway in 21170 working face of Yima Changcun Mine , Using on-site testing, numerical simulation, theoretical analysis and on-site testing methods to analyze the destruction characteristics of large-section support roadway, study the deformation and ring-breaking characteristics and support theory of large-section support roadway, large-section support Factors inducing deformation and failure of roof coal roadway, finally, the support technology of large section supporting roof coal roadway was determined and the expansion plan of 21170 working face roadway was determined.