Abstract: To provide references for improving the quality of crayfish (Procambarus clarkii) meat, we studied the differences in muscle metabolites of crayfish fed with two diets by a non-targeted metabolomic method using liquid chromatography mass spectrometry. Different metabolites in meat were screened by principal components analysis (PCA), cluster analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The results show that 27 significantly different metabolites were screened under the positive and negative ion modes. Compared with the control group (General feed), the contents of adenylsuccinic acid, phosphatidylcholine, quinate, psoralen, phosphatidylserine and glutamic in the experimental group (Fermented feed) increased significantly. According to KEGG pathway analysis, the top four pathways with the highest concentration of metabolites were histidine metabolism pathway, arginine proline metabolism pathway, protein digestion and absorption metabolism pathway, as well as -tRNA synthesis pathway. The results indicate that diets play a positive role in regulating amino acid metabolism, protein synthesis and assisting in the synthesis of aminoacyl-tRNA enzymes in organisms.