Gastric cancer (GC) is a common malignant disease that has a fifth highest incidence and fourth highest mortality worldwide. The Warburg effect is a common phenomenon observed in tumors, which suggests that tumor cells would enhance glucose uptake by overexpressing multiple glucose transporters. Sodium glucose transporter 2 (SGLT2) is one of glucose transporters which highly expressed in several cancers, but its role in gastric cancer is still unclear. Our research found that there was a high expression level of SGLT2 in gastric cancer tissues. We found that Dapagliflozin (a SGLT2 inhibitor) could suppress gastric cancer cell proliferation and migration in vitro and tumor growth in vivo. In present study, we revealed how dapagliflozin would suppress gastric cancer progression in a novel mechanism. We proved that dapagliflozin decreased the expression level of OTU deubiquitinase 5 (OTUD5), which further increased the ubiquitination and degradation of YAP1. Overexpression of OTUD5 in gastric cancer cells partly reversed the anti-tumor effect of dapagliflozin. Our findings revealed a novel mechanism by which dapagliflozin has an antitumor effect on gastric cancer and proposed a beneficial strategy for the application of dapagliflozin in gastric cancer patients.