To investigate the effect of roasting degrees on physicochemical properties and flavor substances of Yunnan sun-dried and washed coffee beans， chromatic aberration， crude fat content， fatty acid content， and amino acid content of sun-dried and washed beans with different roasting degrees were measured. Their volatile compounds were analyzed using gas chromatography-time of flight-mass spectrometry (GC-TOF-MS) and gas chromatography-ion migration spectroscopy (GC-IMS). The GC-TOF-MS results showed that a total of 142 volatile compounds were identified in the 6 samples， and a total of 35 compounds with OAV≥1 were selected through odor activity value (OAV) analysis， which made an important contribution to the overall aroma of Yunnan coffee beans； partial least-squares discriminant analysis (PLS-DA) can better distinguish between sun-dried beans and washed beans； 53 volatile compounds with VIP values＞1 were identified through variable importance in projection (VIP) analysis of PLS-DA. By GC-IMS analysis， 105 volatile compounds were identified qualitatively. The fingerprint showed that 2-methyl-1-propanol， 3-pentanol， 2，3-butanediol and (E)-β-caryophyllene are the characteristic volatile compounds of sun-dried beans， 2-hexanone， octanoic acid ethyl ester， 1-terpinen-4-ol， 1-phenylethanone， 4-methyl-2-pentanone and β-myrcene are characteristic volatile compounds of washed beans； principal component analysis (PCA) can accurately distinguish Yunnan sun-dried beans and washed beans with different roasting degrees. This study utilized GC-TOF-MS and GC-IMS techniques combined with PLS-DA and PCA methods to characterize the flavor compounds of Yunnan sun-dried beans and washed beans with different roasting degrees， and screened out characteristic volatile compounds， providing theoretical reference for elucidating the aroma characteristics of two post-harvest processing methods of coffee beans.