Enrichment analysis of GO function and KEGG pathway were performed on 35 potential targets, and a drug―target―signaling pathway―disease network was constructed to find the action pathway of sitagliptin targeting ACE2 for T2DM: ACE2/Ang-(1-7)/MasR axis in coronavirus disease―COVID-19 signaling pathway. The gene discussed is ACE2; the disease is type 2 diabetes mellitus.