Abstract: In this study, we used simultaneous distillation extraction ( SDE) to extract the volatile components of yak milk powder with ethyl ether as extraction solvent, and analyzed the volatile flavor compounds by gas chromatography-mass spectrometry ( GC-MS) and gas chromatography-olfactometry-mass spectrometry ( GC-O-MS) .The sensory evaluation of yak milk powder was carried out by eight sensory evaluators, the results showed that the color of the sample was well, the flavor of milk, cream and sweet taste was intense.Meanwhile, the sample tasted a slight salty and cooked flavor, without bitter, sour and astringency flavor.In the yak milk powder, 21 kinds of volatile compounds were detected by GC-MS and GC-O-MS simultaneously, including 8ketones, 3 aldehydes, 3 olefins, 2 alcohols, 2 heterocycles, 2 phenols, and 1 ether. Among them, alcohols and ketones were very abundant, the contents were 46.85 μg/m L and 38.63 μg/m L, respectively. This study indicated that the combination of GC-O-MS, GC-MS and sensory evaluation is very accurate and efficient on the analysis of yak milk powder's flavor.