Computer simulation can help to analyze temperature field during deformation, thickness variation of sheet metal and distribution of stress and strain, etc. in the hot forming process, according to numerical simulation of hot stamping, conclusions would be found: sheet metal must be formed within one second with pressing speed between 50mm/s and 150mm/s, and temperature before stamping should be lower than 900°C¹ and higher than Ac₁, temperature after forming should be higher than Ms, and quenching with ten seconds is enough for the request. Experiments have made to prove the simulation.