A total of 81 main aroma compounds were identified by liquid-liquid extraction （LLE） and headspace solid-phase microextraction （HS-SPME） combined with gas chromatography-olfactometry （GC-O） and gas chromatography-mass spectrometry （GC-MS） in Moutai Baijiu. Among them， 69 aroma compounds were detected from the extracts extracted by LLE， mainly containing esters， alcohols and acids； a total of 57 kinds of aroma compounds were detected from the extracts extracted by HS-SPME， mainly containing esters， alcohols and aldehydes. Based on the dilution factor （FD） value and odor activity value （OAV） of aroma compounds， a total of 45 aroma compounds were identified as the key aroma compounds in Moutai Baijiu. The perceptual interactions among three key ester aroma compounds were further studied. The results of S-curve method and OAV method showed that ethyl hexanoate mixed with ethyl acetate or ethyl lactate had synergistic effect， and the addition effect occurred after the mixture of ethyl acetate and ethyl lactate. The results of Vector model showed that the mixture of these three aroma compounds may show a similar interaction effect in most cases.