Abstract: In order to optimize the processing conditions of crisp grass carp(Ctenopharyngodon idellus C. et V)fillets,the best conditions were determined by a single factor experiment and an orthogonal experiment with fresh crisp grass carp(Ctenopharyngodon idellus C. et V)fillets. The best processing conditions were found as follows:10%(m/v)salt solution,the curing time of 15 min,and the solid-liquid ratio of 1:4.Headspace solid-phase microextraction(HS-SPME)and gas chromatography-mass spectrometry(GC-MS)was used to analyze the changes of key volatile flavor substances in the processing. The volatile flavor substances were mainly alcohols and aldehydes,the higher contents of flavor substances had 1-octene-3-alcohol,nonanal and so on. Most importantly,the ROAV value of nonanal was higher than the average of each factor under the condition of 10% salt concentration,curing time of 15 min and solid-liquid ratio of 1:4 conditions. As result,1-octene-3-alcohol,nonanal contributed to the flavor of crisp carp fillets. The orthogonal experiment results showed that the order of the processing conditions affect the flavor of crisp grass carp(Ctenopharyngodon idellus C. et V)fillets were salt solution(m/v),curing time and solid-liquid ratio.The results of this experiment could provide reference for the processing route of crispgrass carp and provide a theoretical support for processing technology.