Coreopsis tinctoria Nutt. (C. tinctoria Nutt.) can protect diabetic kidneys, but the mechanisms are unclear. This work is to investigate the potential mechanisms of C. tinctoria Nutt. in the treatment of diabetic nephropathy based on network pharmacology analysis of its active ingredients. Twelve small molecular compounds of C. tinctoria Nutt. and targets related to diabetic nephropathy were docked by Discovery Studio 3.0. DAVID database was used for GO enrichment and KEGG pathway analysis. Cytoscape 3.6.1 was used to construct active ingredient-target network. Cell viability was detected with MTT. Glucose consumption was analyzed with glucose oxidase method. Protein expression was measured with Western blot and immunofluorescence. Electron microscopy observed autophagosomes. The core active ingredients of C. tinctoria Nutt. included heriguard, flavanomarein, maritimein, and marein. Twenty-one core targets of the 43 potential targets were PYGM, TLR2, RAF1, PRKAA2, GPR119, INS, CSF2, TNF, IAPP, AKR1B1, GSK3B, SYK, NFKB2, ESR2, CDK2, FGFR1, HTRA1, AMY2A, CAMK4, GCK, and ABL2. These 21 core targets were significantly enriched in 50 signaling pathways. Thirty-four signaling pathways were closely related to diabetic nephropathy, of which the top pathways were PI3K/AKT. insulin, and inTOR, and insulin resistance. The enriched GO terms included biological processes of protein phosphorylation, and the positive regulation of PI3K signaling and cytokine secretion; cellular components of cytosol, extracellular region, and extracellular space; and molecular function of protein kinase activity, ATP binding, and non-membrane spanning protein tyrosine kinase activity. In vitro experiments found that marein increased the expression of phosphorylated AKT/AKT in human renal glomerular endothelial cells of an insulin resistance model induced by high glucose, as well as increased and decreased. respectively, the levels of the microtubule-associated proteins, LC3 and P62. C. tinctoria Nutt. has many active ingredients, with main ingredients of heriguard, flavanomarein, maritimein, and marein, and may exert anti-diabetic nephropathy effect through various signaling pathways and targets.