Abstract: To improve the quality of wheat and wheat flour and meet the wheat flour mill cleaning requirements, a new technology of wheat classification in three grades was designed by using the gravity grading destoner and gravity separator in China.The experiment was carried out with common wheat with medium and strong gluten.The raw material wheat was classified and then separated into different samples.The physicochemical indexes of each grading wheat grain were studied.The wheat selected at each grading stage was milled separately, and then the pasting, farinograph and extensograph properties of each sample of wheat flour were studied.The results showed that the test weight, 1000-kernel weight and flour yield of heavy wheat of each grading stage were significantly higher than that of light wheat, and the content of unsound kernels and DON was significantly lower than that og light wheat, and the wheat grading significantly improved the quality of heavy wheat.The falling number, damaged starch and gluten index of heavy wheat flour were significantly higher than that of light wheat flour.The whiteness of heavy wheat flour was slightly higher than that of light wheat flour.The water absorption of heavy wheat flour was higher than that of light wheat flour, the stability time and the farinograph quality number of heavy wheat flour were also higher than that of light wheat flour.The degree of softening of heavy wheat flour was significantly lower than that of light wheat flour.The flour quality of heavy wheat obtained by wheat grading was significantly improved.The gelatinization viscosity of heavy wheat flour obtained by wheat grading was significantly higher than that of light wheat flour, breakdown was significantly lower than that of light wheat flour, and there was no significant difference in gelatinization temperature.At each grading stage, the maximum resistance, extensibility and maximum tensile ratio of heavy wheat flour were significantly higher than that of light wheat, and the gluten of heavy wheat flour dough was stronger than that of light wheat flour.The resistance, tensile ratio, extension energy and extensibility of the three kinds of wheat flour selected by the third classification decreased in order of heavy wheat, mixing wheat and light wheat.Therefore, the wheat grading technology can improve the quality of wheat and wheat flour significantly.The flour quality is improved greatly with this wheat grading process, and this technology is beneficial for millers to maximize profits.