Taking advantage of the temperature-increasing effect of inorganic molten salt hydrates, catalytic wet air oxidation of chloroacetic acid (CAA) wastewater under low pressures was conducted. The effects of catalyst type, reaction temperature and reaction time on the removal of CAA and COD were investigated. It was found that CuCl2 has the highest catalytic performance in dihydrate of CaCl2 among the tested catalysts. The removal rates of CAA and COD can reach up to 95% and 90% respectively. The free radical inhibition experiments and intermediate products analysis revealed that the catalytic oxidation mechanism is that CAA degrades to glycolic acid, formic acid and finally to CO2 and water in turns under the synergistic catalysis of hydroxyl free radicals that is generated by the interaction of oxygen with the catalyst cycle of Cu(Ⅱ)-Cu(Ⅰ)-Cu(Ⅱ).