Objective: This study aimed to investigate the effect of milling rate on the composition of volatile substances in indica rice. Methods: Indica rice with the ideal milling rate of 0%～14% was prepared from indica rice " Longkezao 1", and the effect of milling degree on the sensory quality of indica rice after cooking was investigated. The volatiles of indica rice after cooking were determined by gas chromatography-ion mobility spectrometry （GC-IMS）. The differences of volatiles of rice with different milling rates were analyzed by fingerprinting and multivariate statistics. Results: The highest sensory scores were obtained for indica rice at a milling degree of 8%. The volatile substances in rice were mainly aldehydes, ketones, and some alcohols and furans. Most of the volatile components were higher in indica rice with a milling degree of 0%～6%, and there was no significant difference in the composition of volatile substances in the rice when the milling degree was 10%～14%. Among them, 2-methyl-1-butanol, isoamyl acetate, isoamyl alcohol, 2-pentenal, 3-methylbutyric acid, and 2-ethylfuran were used as the volatile substances of rice with different milling rates of "Longkezao1". The volatiles were found to be different in rice with different milling rates. Conclusion: Milling processing can reduce the volatile components content of brown rice, 8% of the milling degree can make the rice have good odor and sensory quality.