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Green tea dust was used as raw material in this study. The polyphenols in the green tea dust were extracted by a solid-liquid ratio of 1:20 g/mL, extraction temperature of 85 °C, ethanol concentration of 60% and extraction time of 60 min, and solvents with different polar were employed to extract and separate and the bioactive components in the green tea dust into 4 fractions. The mass concentration of total phenols contained in the different fractions was determined, and the bioactivates of different fractions were evaluated through free radical scavenging assay, and their inhibitory activities on pancreatic lipase and α-amylase were also studied. The results showed that the ethyl acetate extracted fraction had the highest total polyphenol content (15.66 mg/mL) and the strongest bioactivities among all the fractions. Its IC50 for the free radical scavenging rate of DPPH and ABTS were 0.05 mg/mL and 0.15 mg/mL, respectively, and inhibitory activities on pancreatic lipase and α-amylase were IC50 0.89 mg/mL and 0.39 mg/mL, respectively. The polyphenols in the ethyl acetate extracted phase were further characterized and quantified by HPLC and MS. A total of 15 polyphenolic compounds were identified by MS and was first identified of phlorizin (5.44 mg/g) in green tea dust. Quantitative analysis of the compounds with high contents by HPLC revealed that epigallocatechin, catechin and chlorogenic acid were present at high contents of 72.03 mg/g, 48.62 mg/g and 41.58 mg/g respectively. [ABSTRACT FROM AUTHOR]