In order to analyze and study the influence of different width of high water filling body on roadway surrounding the roadway along the goaf, the 12305 working face of Yunjialing Mine was taken as the research background, and the evolution law of stress and strain of surrounding rock was studied by FLAC3D numerical simulation software when the width of the filling body was 2 m, 3 m and 4 m respectively. The results showed that the larger the width of the filling body was, the smaller the lateral support pressure was, the greater the relative deformation of the coal side, the greater the bearing and deformation of the filling body. When the width of the filling body was 3 m, the adaptability of the backfill and the roof was better, and so was the stability of the surrounding rock, and the field practice was verified by the field practice.