Knee osteoarthritis is a common chronic joint disease. Although there are many treatment options available for knee osteoarthritis, most focus on alleviating symptoms rather than halting disease progression, repairing cartilage, reversing joint damage, or restoring the structure and function of the knee. Hyperbaric oxygen therapy works by increasing tissue oxygen concentrations by increasing higher atmospheric pressure. This therapy can directly improve the hypoxic microenvironment in knee osteoarthritis. Hyperbaric oxygen therapy can also improve oxygenation, reduce oxidative stress and regulate inflammatory responses. In addition, it plays an important role in promoting angiogenesis, cartilage repair and regeneration, and healing of damaged joint tissue. This review explores the therapeutic effect of hyperbaric oxygen therapy on knee osteoarthritis, systematically analyzes its therapeutic mechanism, potential advantages and current limitations, and provides direction for future research. As it continues to develop, hyperbaric oxygen therapy has the potential to become a non-invasive, efficient and highly targeted treatment option, bringing new hope to patients with knee osteoarthritis.