Abstract: The structural form of hanging roof trusses by a main trussed arch was used for the steel roof of the sports and culture gymnasium in Beijing Institute of Technology，whose main arch was a circular arch composed of steel tubular trussed，and the roof truss was a curved truss composed of steel tubes． It was expounded the main process of quality control of the steel roof of the gymnasium by means of the quality management in the stages of optimization design，member processing，construction and erection of the steel main arch and steel trusses．