Polydatin, with better structural stability and biological activities than resveratrol, is mainly extracted from the traditional Chinese medicinal plant Polygonum cuspidatum. In this study, based on the transcriptome analysis of P. cuspidatum, we identified the key glycosyltransferase of resveratrol and achieved the biosynthesis of polydatin from glucose by incorporation with the resveratrol biosynthesis module, UDP-glucose supply module, and glycosyltransferase expression module. Through metabolic engineering and fermentation optimization, the production of polydatin reached 545 mg/L, and the dry cell weight was 27.83 mg/g DCW, which was about twice that of extracted from the P. cuspidatum root (11.404 mg/g DCW). Therefore, it is possible to replace the production mode of polydatin from plant extraction to microbial chassis in the future.