To explore the browning reaction of rhubarb and qualitatively analyze the chemical components of rhubarb.The chemical components of rhubarb were analyzed and identified by UPLC-MS/MS technology,the color of rhubarb cut surface was determined by colorimeter technology,and the ebb and flow of components,substrate gallic acid and products of each sample were detected by HPLC technology,and LC-MS technology was used.The browning products were detected,and the binding ability of tyrosinase to gallic acid,catechin,epicatechin,emodin,etc.was predicted by molecular docking technology.The chromatographic peak area of each sample of rhubarb decreased to varying degrees during the fresh-cut and air-drying process.A total of 30 compounds were identified by UPLC-MS/MS,mainly including phenolic acids,anthraquinones,flavanols and others.The color of the cut surface of rhubarb and the color of the reaction system changed obviously,the peak area of the substrate gallic acid decreased obviously,and new substances were formed,indicating that the rhubarb had an enzymatic browning reaction.The molecular docking results showed that the complex aminase had good affinity with gallic acid,catechin,epicatechin and rhodopsin,which provided some basis for further investigation of the relationship between enzymatic browning and anthraquinone components from anthraquinones subsequently.