Abstract: This paper analyzes the generation and treatment of mixed oil and distillate during the current operation of Lanzhou-Zhengzhou-Changsha Products Oil Pipeline, and indicates the reasons why the treatment of distillate in some area fails to meet the demand on the market. Considering the current conditions of the pipeline and the management of oil depots, this paper puts forward proper and effective measures for mixed oil treatment, including the improvement of supporting facilities for storage and transportation such as loading and unloading of vehicles, sale of oil mixed with highgrade oil, optimization of operational process of topping unit, optimal design of topping unit, seeking for policy support, and comprehensive consideration of field situations and economic benefits, so as to increase the transportation turnover of pipeline and effectively guarantee safe and stable operation of pipeline.