Abstract: Commercial FEM program LS-DYNA has been used to do the simulation of thermal residual stress in H-beam’s air cooling,with the thermal mechanical coupled method and the whole rolling process simulation result used as the initial thermal field.The residual stress field results of H-beam in different lengthes have been obtained.The simulation results show that the residual stress condition was complicated by the ununiformity of cross section’s thermal field.In the direction of length,the residual stress at the web manifested compressive stress and in the whole could reach 160 MPa,while that at the web center and at the connect position betweeen web and flange manifested tensile stress.The residual stress condition in the direction of width influenced the distribution of the residual stress in the direction of length.While the length was less than 3 m,the residual compressive stress decreased as the hot cut length was shortened.