Objective:The effect of microwave heating on nutrition and flavor composition of crayfish was investigated.Methods:After pre-treatment, the nutrition and flavor changes of crayfish without microwave treatment, 210 W microwave and 350 W microwave treatment for 5 min were analyzed respectively.Results:The results showed that low power microwave treatment did not significant affect the crayfish water content, which was obvious loss under the condition of 350 W microwave. In dry samples, the microwave power had no significant effect in crude ash, while the total sugar and crude fat was affected with a decrease tendency. However, the microwave power significantly increased the crude protein content. Microwave heating had a significant effect on the unsaturated fatty acids in crayfish, and the contents of total amino acids and essential amino acids decreased with the microwave power increase, with a high nutritional value maintained. With the increase of microwave power, the contents of flavor components in crayfish decreases, such as umami amino acids, sweet amino acids and flavored nucleotides. Both the taste activity value and the equivalent umami concentration were lost obviously.Conclusion:Microwave heating treatment can cause the nutrient loss of crayfish, in an acceptable range. However, microwave power cna significant decrease the fresh flavor and taste of crayfish, showing a linear trend.