Objective To investigate the effects of thermal treatments (dry heat, microwave, and high-temperature high-pressure steam) and high-pressure defatting processes (supercritical CO₂ extraction and ultrasound-assisted subcritical n-butane extraction) on the quality of rice bran, aiming to improve its stability and potential for high-value utilization.Methods Rice bran was pretreated by dry heat, microwave, and high-temperature high-pressure steam, combined with two high-pressure defatting techniques. The effects on lipase activity, storage stability, and physicochemical properties of rice bran were systematically analyzed.Results High-temperature high-pressure steam treatment (121 ℃, 20 min) significantly reduced lipase activity to 19.87 mg/g and effectively inhibited the accumulation of free fatty acids during 30 days of storage, demonstrating superior stabilization compared to dry heat and microwave treatments. Supercritical CO₂ extraction achieved an oil yield of 97.73%, outperforming ultrasound-assisted subcritical n-butane extraction, and significantly improved the water-holding capacity (3.08 g/g), swelling capacity (5.82 g/g), and water solubility index of rice bran.Conclusion The combination of high-temperature high-pressure steam treatment and supercritical CO₂ extraction markedly enhanced the storage stability and functional properties of rice bran.