This wet catalytic oxidation method is based on the wet air oxidation method. This method is the WAO method (abbreviated as WACO method) for wastewater treatment. This method is mainly used to treat high-concentration organic wastewater that is difficult to decompose. This is a potentially effective technical method. The high temperature of 200~280°C and the high pressure of 2~8mpa, oxygen-enriched gas or oxygen are used as catalysts, and the respiration reaction rate of organisms in wastewater passes through the catalyst faster.