Exploring the effect of milling degree on rice flour quality is very important to develop rice processing mechanism for suitability. The composition, X-ray diffraction, gelatinization, rheological and gel texture and structure of rice flour under different milling degree were determined. The results suggested that with the milling degree increased, the protein content decreased from (11.24±0.06)% to (7.89±0.27)%, and the amylose content increased from (8.51±0.27)% to (25.93±2.42)%, with the increase of XRD absorption peak of starch. The peak gelatinization viscosity increased from (2 025±169.2) cp to (4 847±140.5) cp, and the gelatinization temperature decreased from (71.82±0.67) ℃to (70.1±0.04) ℃. With the increase of the viscosity and elasticity and the decrease of the fluidity of rice flour paste, the gel microstructure region was found uniformed and compacted well. This indicated that milling could reduce the protein content of rice flour, increase amylose content and promote the gelatinization and short-term aging of rice flour, and the promotion effect was strengthened with the increase of milling degree.