Objective:To discuss whether hyperbaric oxygen（HBO）can enhance the drug sensitivity of Hela cells to cisplatin（DDP）and how does it work.Methods:After the Hela cells were cultured，they were divided into control group，DDP group，HBO group，and HBO+DDP group. The control group was not treated. The DDP group was treated with 20 μmol/L DDP for 24 h. The HBO group was treated with 0.2 MPa HBO for 3 h，and the HBO+DDP group was treated with 20 μmol/L DDP for 24 h after HBO pretreatment for 3 h. The proliferation of Hela cells was detected by CCK-8 assay，and the apoptosis of Hela cells was detected by flow cytometry. Transwell assay was used to detect the migration ability of Hela cells，and western blotting was used to detect the expression levels of proteins related to the apoptosis of Hela cells.Results:The Hela cells survival rate in the DDP group was significantly lower than those in the control group and the HBO group，and was higher than that in the HBO+DDP group（ P<0.05）. The migration rate of Hela cells in the HBO+DDP group［（19.61±1.53）%］was significantly lower than that in the DDP group［（48.19±2.47）%］，and the difference was statistically significant（ P<0.05）. The apoptosis rate of Hela cells in the HBO+DDP group［（58.68±3.69）%］was significantly higher than that in the DDP group［（35.74±3.57）%］，and the difference was statistically significant（ P<0.05）. The protein expression levels of Bad and caspase-3 in Hela cells in the HBO+DDP group were significantly increased and the protein expression of Bcl-2 was significantly decreased compared with those in the DDP group，and the differences were all statistically significant（ P<0.05 or P<0.01）. Conclusion:The combination of HBO and DDP can improve the sensitivity of Hela cells to cisplatin chemotherapy by enhancing the proliferation inhibition，apoptosis-inducing，and migration-blocking effects of DDP on Hela cells.