Abstract: The influence of major technical parameters，such as reaction temperature，feed organic concentration of wastewater，liquid flow rate etc. On the effect of catalytic wet oxidation (CWO) of spent caustic wastewater pretreated through acidification and neutralization was investigated in the trickle bed reactor (TBR) which was filled with catalyst MnOx/γ-Al2O3. The result indicated that temperature and liquid flow rate were two key factors that influence the reaction. The rate of reaction could be greatly increased with an increase of temperature，and the slower the liquid flow rate，the better the performance. High dissolution of metal ions in the first 15hr of continuous operation time was found，but was stabilized later and did not afffect the activity of the catalysts. The high catalyst-liquid ratio in the trickle-bed resulted in very fast reaction rate of spent caustic wastewater.