Abstract: To systematically analyze the differences in flavor composition among five representative chili oils made from Ningxia Yangjiaojiao, Shaanxi Qinjiao, Guizhou Mantianxing, Guizhou Denglongjia and Sichuan Erjingtiao peppers, this study employed multi-dimensional detection techniques, including electronic nose (E-nose), headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS). Chemometric approaches such as principal component analysis (PCA) and orthogonal partial least squares-discrimination analysis (OPLS-DA) were applied, combined with odor activity values (OAV) to identify key differential aroma compounds. The results demonstrated that PCA based on E-nose data could effectively distinguished the five chili oil varieties, with significant differences (P<0.05) observed in the responses of W2S and W1W sensors, indicating notable variations in the content of alcohols, aldehydes, ketones, inorganic sulfides, and terpenes. A total of 41 and 99 volatile compounds were identified in the five chili oils via GC-IMS and HS-SPME-GC-MS, respectively. Among them, 14 key differential compounds with variable importance in projection (VIP)>1 were screened from GC-IMS, including 6 aldehydes, 5 ketones, 1 alcohol, 1 ester, and 1 aromatic hydrocarbon, which contributed significantly to fruity, sweet, nutty, fatty, and pungent notes. From HS-SPME-GC-MS, 17 key differential aroma compounds with both VIP>1 and OAV>1 were identified. Correlation analysis between sensory attributes and key differential aroma compounds revealed that (E)-2-octenal, methional, anethole, 2-pentylfuran, and 5-methylfurfural were closely associated with nutty, caramelized sweet, and fatty notes; hexanal, heptanal, 1-pentanol, (E)-2-hexenal, benzaldehyde, 1-octen-3-ol, and nonanal were correlated with greasy and smoky notes; while 2,3-pentanedione, toluene, 2-ethyl-6-methylpyrazine, 3-methylbutanal, and phenylacetaldehyde were correlated with green and pungent notes. Overall, the Sichuan Erjingtiao chili oil exhibited the best overall aroma profile, characterized by typical meaty and sweet notes, primarily attributed to methional, 2-pentylfuran, and 5-methylfurfural. The Shaanxi Qinjiao chili oil displayed the richest aroma characteristics with a strong spicy fragrance, mainly derived from 2-ethyl-6-methylpyrazine. The Guizhou Denglongjiao chili oil exhibited a unique floral aroma, largely contributed by 1-octen-3-ol and 2,3-pentanedione. In contrast, the Guizhou Mantianxing and Ningxia Yangjiaojiao chili oils showed less distinct aroma characteristics, indicating relatively weaker sensory qualities. By elucidating the compositional differences in aroma characteristics of chili oils from different pepper varieties, this study aims to provide a theoretical foundation for the flavor-oriented development and quality control of high-quality chili oils.