Abstract: Taking Shaanxi Binchang Mining Area 4^# coal seam roadway as the research background, using filed industrial practice method, the loose circle range between two sides of the roadway under the influence of the mining and tunneling process is determined through the measure carried out in mining face and heading face. Based on this, the internal structure of the coal body is analyzed and the internal damage situation of coal body is judged, which provides the designing basis for determining the length of the two groups of bolt support. The test is also an important basis for the evaluation of surrounding rock stability of the coal seam.