Abstract: The effects of deep-frying and air-frying on physicochemical characteristics, microstructure, free amino acids, fatty acids and volatile components of hairtail were analyzed. The results showed that under the same frying temperature (190 ℃), with the increasing of the frying time, the moisture content and production rate of hairtail decreased, but hardness and chewiness increased. The redness of deep-frying hairtail improved significantly, but brightness decreased. The skin of air-frying hairtail was kept intact and there was no significant change in the brightness (P>0.05). Combining sensory assessment and physicochemical characteristics, under 190 ℃ deep-frying for 7 min and the air-frying for 24 min were selected. Further researchs found that the myofiber bundle gap in deep-frying hairtail was large and fractured, but the air-frying hairtail was closely arranged and orderly. The ratio of essential amino acid to total amino acid in air-frying hairtail was up to 45.41%, which belonged to high quality protein, while deep-frying samples was less than 40%. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of air-frying hairtail were significantly higher than that of deep-frying sample (P<0.05). The content and species of volatile flavor substances in the hairtail differed to different degrees. To sum up, there were some differences in the quality and flavor between air-frying and deep-frying hairtail, which would provide a theoretical reference for the processing method of fried hairtail.