Objective: To clarify the differences of volatile aroma substances among rice， rice and cooked rice under acidic conditions， and to provide data support for the analysis of volatile flavor differences in the distillation process of nong-flavor liquor. Methods: Headspace solid phase microextraction-comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (HS-SPME-GC-TOFMS) was used to identify volatile aroma compounds in raw rice (broken rice flour) and cooked rice (cooked rice， cooked rice with acid). The differences of volatile flavor compounds between samples were analyzed by orthogonal partial least squares discriminant analysis (OPLS-DA) and aroma activity value(OAV). Results: A total of 98 volatile flavor substances were identified in broken rice flour， rice and rice with acid， which were 65，55 and 68 volatile substances， respectively， of which 31 were common substances. The number and content of substances were mainly alcohols， aldehydes， esters and ketones. Based on the content of volatile flavor compounds in the three samples， OPLS-DA analysis was carried out. The results showed that there were 54 different substances with VIP > 1 in the three samples. Among them， there were 24 substances such as 2-heptanone， 2，3-octanedione and dihydro-5-pentyl-2(3H)-Furanone in broken rice flour， 6 substances such as 3-thiophenecarboxaldehyde， 2，3-pentanedione and 2，6，6-trimethyl-2-cyclohexene-1，4-dione in rice， and furfuryl alcohol， furfural and thearone in rice with acid. Isovaleric acid and other 24 kinds. OAV analysis showed that ethyl caproate had higher OAV values in the three samples， and the OAV of 2-acetyl-1-pyrroline in broken rice flour and rice was > 10. The highest OAV value in acid-added rice was ethyl caproate， and 2-acetyl-1-pyrroline was not detected in acid-added rice. The OAV values of 1-octene-3-ol， nonanal， ethyl caproate and other substances increased to varying degrees compared with the substances with OAV > 0.1 in rice. These substances with OAV > 0.1 could assist the overall aroma presentation， which was one of the reasons for the difference in aroma between rice and rice with acid. Conclusion: HS-SPME-GC-TOFMS combined with OPLS-DA and OAV were used to explore the differences of volatile compounds between raw rice， cooked rice and cooked rice under acidic conditions， so as to provide data reference for clarifying the effect of nong-flavor liquor on the extraction of volatile flavor substances in rice during ‘mixed steaming and mixed burning’.