Abstract: In order to increase the percentage of head milled rice after polishing process, the effects of temperature, relative humidity and initial water content on the time of deformation relief were studied by quadratic regression rotary combination experiments. Taking rice as raw material, the head rice rate of polished rice after deformation relief were compared with that of traditional method. Excel and SAS software were employed to analyze the experimental data, and the relative mathematical model was established. The results showed that within the experimental parameters rang (temperature 5-45℃，water content 13%-17% and relative humidity 25%-85%), 46-69 min could relieve deformation of milled rice, the initial water content, temperature and relative humidity have significant effect on the time of deformation relief. The head rice rate of polishing process after deformation relief is obviously higher than that of directly polishing process. The mathematical model can provide a theoretical support for deformation relief process of rice.