Vibrio parahaemolyticus (V. parahaemolyticus) is a common pathogen for marine crustacean, which causes severe illnesses in aquatic animals. Therefore, it is meaningful to explore the mechanism during V. parahaemolyticus infection. In this study, to investigate the immune responses of mud crab Scylla paramamosain (S. paramamosain) to V. parahaemolyticus, we established the metabolic and transcriptional profiles of mud crab hemocytes challenged with V. parahaemolyticus. The results indicated that V. parahaemolyticus infection could induce a series of metabolism alterations at both metabolome and transcriptome levels, including biosynthesis of amino acids and Aminoacyl-tRNA, Purine and pyrimidine metabolism, TCA cycle and glutamine metabolism. In this context, through the integration of metabolomics and transcriptomics, our study provided a more comprehensive understanding of the biological process in mud crab against pathogen infection.