In response to the high cost of additives per ton of oil in a certain refining and chemical enterprise,a decomposition analysis of the cost composition of the additives is conducted to identify the main reasons affecting the cost of the additives and the reasons for the high cost per ton of oil,especially the higher cost of FCC unit and hydrorefining unit,in which the consumption of catalyst and sodium hydroxide was analyzed. The main reasons for the high cost per ton of oil are the influence of the overall processing technology and the geographical location factors. In view of the main reasons found,the suggestions for extending the life of the hydrogenation catalyst and reducing the price of the sodium hydroxide solution are put forward.