Abstract： Objective： Base on UPLC- Q- Exactive- Orbitrap- MS(LC- MS) and molecular docking， to study the active ingredients and mechanisms of Hedyotis Diffusa Willd Injection in the treatment of gastric cancer. Methods： LC- MS was used to identify the chemical constituents of Hedyotis Diffusa Willd Injection，Gastric cancer related targets were predicted from the GeneCards database， the protein- protein interaction PPI was constructed by STRING detabase and Cytoscape software， and the molecular docking technology was used to verify the relationship between disease targets and the chemical constituents in Hedyotis Diffusa Willd Injection. Results： 22 chemical constituents were identified in Hedyotis Diffusa Injection，and There were 35 target proteins of drug-disease intersection，TP53、PTEN、PIK3CA、MLH1 and KRAS were the core target proteins.Molecular docking results showed that breviscapine， 3- arabinose glucosylquercetin， pinotriose，quercetin-3-rhamnoside，maltotriose，palagin and hydroxyisogeniposide had a good binding effect with one or more targets of TP53， PTEN， PIK3CA， MLH1 and KRAS. Conclusion： Breviscapine， 3- arabinose glucosylquercetin and pinotriose are the main active components of Hedyotis Diffusa Willd Injection in the treatment of gastric cancer. Its mechanism may be related to the targets of gastric cancer TP53，PTEN，PIK3CA，MLH1 and KRAS.