To explore the chemical constituents of Simotang oral liquid by high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS/MS),and to explore Simotang oral liquid with network pharmacology The main active components and mechanisms of prevention and treatment of depression.Liquid-mass method was used to accurately analyze the blood components of the patent medicine;PubChem Compound,SwissTargetPrediction and other databases were used to predict the protein targets of blood components;at the same time,the disease targets of depression were retrieved from OMIM and GeneCards,and the components and diseases were selected.The intersection targets are used as a protein target library.Enter the intersection targets on the STRING online data platform,set the search condition "Homo sapiens",and analyze the interaction between their proteins.The intersection target information was input into Cytoscape 3.7.1 for visual network analysis,and PPI network was constructed;GO enrichment analysis and KEGG pathway enrichment analysis were performed on drug efficacy disease targets.Finally,draw a network diagram of "blood entry components-action targets-action pathways";try to screen out the key pharmacodynamic material basis,and preliminarily explore its mechanism of action.A total of 20 chemical components were identified from the plasma samples of Simotang oral liquid;the "component-target-pathway" network map involved 19 compounds,181 targets and 20 pathways.Active ingredients are boldine,norisoboldine,isoboldine,limonin,isorhamnetin;targets related to depression are PI3-kinase p110-gamma subunit (PIK3CG),dual specificity mitogen-activated protein kinase1(MAP2K1),mitogen-activated protein kinase1(MAPK1),PI3-kinase p110-alpha subunit (PIK3CA),protein kinase C alpha (PRKCA).Simotang oral liquid may play a role in the prevention and treatment of depression mainly by participating in inflammatory response,neuronal apoptosis,cell physiology,oxidative stress and immune response,and regulating PI3K-Akt,cAMP,5-HT,MAPK and other pathways.