In order to solve the problem of surrounding rock deformation and support failure of coal seam roadway under high ground stress environment, the transportation roadway of No.4 coal seam in Datong coalfield was selected as the research object, and the structural response and optimal control of support system were studied. The stress and deformation monitoring devices were arranged on both sides of the roadway, and the response law of the original support system of ' bolt + anchor cable + metal mesh + shotcrete ' was analyzed. The stress of surrounding rock under the original support was finally stabilized at 13.2,11.0 and 8.6 MPa, the support stress was stabilized at 75.2,58.1 and 50.2 MPa, and the deformation of surrounding rock was stabilized at 48.2,35.2 and 27.3 mm. In view of the original support defects, the parameters of bolt and anchor cable were optimized, the concrete was lifted to C25, and the bottom angle bolt was added. After optimization, the stable value of surrounding rock stress decreased by 29.1 % ~ 36.4 %, the supporting stress decreased by 27.5 % ~ 36.4 %, and the deformation of surrounding rock decreased by 48.7 % ~ 53.5 %. The values were less than the allowable limit, which provided a scientific basis for the support of similar high ground stress roadways.