Abstract： Objective:To investigate the effects and possible action mechanism of hyperbaric oxygen on postoperative healing of osteoporotic fractures.Methods:A total of 98 patients with osteoporotic fractures treated by Department of Orthopedics of Heji Hospital Affiliated to Shanxi Changzhi Medical College between September 2019 and April 2021 were randomly assigned to either the control group or the research group，with 49 patients in each group. In addition to the routine treatments for all patients，e.g.，operative reduction，fixation，functional exercise，and nerve growth factor therapy，the research group was additionally treated with hyperbaric oxygen. The clinical efficacies of the treatments for the two groups were evaluated as follows：The bone mineral density parameters（BMDP）before and after the treatments were measured. The levels of insulin like growth factor-1（IGF-1），soluble intercellular adhesion molecule-1（sICAM-1），inflammatory factors［interleukin-1（IL-1），interleukin-6（IL-6），and tumor necrosis factor-α（TNF-α）］，oxidative stress factors，and serum bone metabolism parameters were determined by enzyme-linked immunosorbent assay（ELISA）. The urine creatinine level was measured by picric acid method，and the cross linked N-terminal peptide of urinary type I collagen / creatinine（uNTx/Cr）value was calculated.Results:The clinical effective rate of the research group（95.92%）was significantly higher than that of the control group（83.67%），with statistically significant difference（ χ2=4.009， P<0.05）. After the treatment，the levels of N-terminal middle molecular fragment of osteocalcin（N-MID），IGF-1，and sICAM-1 were increased（ P<0.05）in both groups；and the increases in the research group were significantly higher than those in the control group（ P<0.05）. Compared with the control group after the treatment，the levels of SOD，total antioxidant capacity（T-AOC），bone alkaline phosphatase（BAP），and osteocalcin（OC）in the research group were more significantly raised；and the levels of advanced oxidation protein products（AOPP），metabolic enzyme monoamine oxidase A（MAOA），IL-1，IL-6，TNF-α，crosslinked C-terminal peptide of type I collagen（CTx），uNTx/Cr，and BMDP in the research group were more significantly reduced，all the differences were statistically significant（ P<0.05）. Conclusion:Hyperbaric oxygen can promote the postoperative healing of osteoporotic fractures，which may be related to its role in reducing inflammation and oxidative stress and improving bone metabolism，hence increased bone density and enhanced healing.