The whole rolling process of HN800 mm×300 mm H-beam produced by LaiGang was simulated by 3D thermal couple numerical simulation. The deformation behavior and the temperature distribution during TM reversible rolling process were analyzed by the excessive deformation of the mesh elements. The results indicate that the main rolling deformation is the flange. With the flange thinning, metal varus will occurs. At the same time, surface temperature difference is between the web and the flange, which can be up to 160 ℃ more or less after 200 s cooling. The research can grasp the rolling deformation and temperature changes, provide the theoretical basis for productive practice.