In order to improve the flavor quality of grass carp (Ctenopharyngodon idella) fish meat, the pond cultured grass carp was used as the research object, and the indoor micro-flow water system was used to treat the grass carp for 0, 1,4, 7d, respectively. Comprehensive two-dimensional gas chromatography-time of flight mass spectrometry technology was employed to screen out the key odor substances at different treatment time. And a metabolomics method based on liquid chromatography-mass spectrometry/mass spectrometry technology was used to study the effects of flavor components of micro-flow water treatment on grass carp. The results showed that the treatment time of micro-flow water had a significant effect on the contents and types of odor components in the meat of grass carp. With the extension of the treatment time, the relative contents of flavor precursors glutathione, oxidized glutathione and polyunsaturated fatty acids increased. The relative contents of the key unpleasant odor compounds of grass carp fish meat, such as grassy hexanal, fishy heptanal, green moldy (E)-2-pentenal and 1-heptanol were reduced. And the contents of umami and sweet amino acids and nucleotides in the flavor substances of grass carp fish meat were accumulated, the bitter amino acid content gradually decreased, thereby improving the texture of the grass carp meat and bringing a rich flavor.