This article mainly researches the influence of the steaming process to the whiteness of the steamed bread.By changing the steam pressure and the times of steaming at the time of the steaming,to make the steamed bread respectively,and mensurate the whiteness.Determine the most proper steam pressure and the times of steaming.The determination result indicated that in the steam pressure small situation,steamed bun the whiteness value assumes the declining trend approximately along with the time passage;in the steam pressure big situation,the whiteness value goes up along with pressure build-up.