Catalytic destructive oxidation of tributyl phosphate (TBP) in supercritical water (SCW) medium was examined. Different nanocatalysts were synthesized using SCW method and their abilities to destruct the TBP in the aqueous solution were compared in order to pick out the best catalyst for the subsequent experiments. The effect of main operational variables, including reaction temperature, time and pressure, and oxidant concentration was investigated in order to determine optimal conditions. A practical mechanism for catalytic oxidation of TBP in SCW was also proposed based on the results of various analyses. The results demonstrated that among all of the catalysts, CeO2 provided the best result in the oxidation process, by which the TOC removal efficiency was increased by 22% with respect to noncatalytic oxidation. In addition, temperature and pressure showed an influential effect on the TBP decomposition efficiency, while the effect of oxidant can be neglected.