Multi-walled carbon nanotubes ( MWCNTs) was used, as a catalyst carrier, to load cerous sulfate for catalyzing the synthesis of n-butyl propionate. The effects of nitric acid concentration, reaction time and reaction temperature on the purification of MWCNTs were investigated. The effects of molar ratio of butyl alcohol to propionic acid, the cerous sulfate load and the reaction time on the conversion of butyl acid were studied by single factor experiment method and orthogonal experiment method, respectively. The results show that the optimal conditions for purifying MWCNTs are: nitric acid concentration of 4 M, reaction time of 8 h and reaction temperature of 103°С and the optimal conditions for synthesizing n-butyl propionate are: molar ratio of butyl alcohol to propionic acid of 1.5:1, use level of loaded cerous sulfate of 0.15 g and reaction time of 70 min. The conversion of butyl acid for the MWCNTs loaded cerous sulfate reaches 96.7% which is higher than that for the unloaded cerous sulfate and the use level of cerous sulfate for the former is much less than that for the latter under same operation conditions.