Abstract: Excess oxygen in the supercritical water oxidation systems usually causes the problem of system operation cost improvement. To solve this problem, a high pressure water absorption principle based method was investigated for the O2 recycle. The Aspen Plus process of supercritical water oxidation system with oxygen recovery and the PSRK model was applied to study the influence of system parameters like pressure and temperature. The analyzing results showed that, with increasing pressure the purity of O2 can be increased but the O2 yield was decreased in the gas phase. With the increasing temperature, the ratio of O2 in gas phase can be increased but the purity of O2 was decreased. When the separator pressure and temperature were set to 8 MPa and 27℃, the ratio and purity of O2 was 89.29% and 83.33% respectively. The material and energy consumption cost of the system was calculated, and the results showed that the material and energy consumption cost was 2.811 ￥/kg chemical oxygen demand (COD). The cost can be reduced 21.01% in comparison with existing supercritical water oxidation system with oxygen recovery. Moreover, the reduction rate of the material and energy consumption cost increases gradually with the increasing of excess oxygen coefficient.