ABSTRACTThere are many oily sludge treatment technologies with great development prospects, and due to the lack of an objective and scientific technology evaluation system, there have been different opinions and views on the selection of technologies. To address this issue, this paper establishes a multi-criteria decision system based on hierarchical analysis and gray decision-making, discusses the weights of oily sludge treatment technologies in terms of economic benefits, technology, environment and social indicators, and categorizes the relevant impact indicators into target level, criterion level and program level, etc. So as to analyze them qualitatively and quantitatively. The results show that in the hierarchical analysis decision system, the order of influence of the weight of each indicator on the research objectives is as follows: technical and environmental impact indicators occupy an absolute advantage for the treatment and disposal of oily sludge, with a weight of 0.5886 for environmental indicators and 0.2074 for technical indicators, whose main impact indicators include the resourceization of oily sludge with a weight of 0.6104 and the pollution degree of soil with a weight of 0.5115. Because X2 shows a high correlation in the evaluation model, the preferred oily sludge and blast furnace slag catalytic pyrolysis treatment, a comprehensive evaluation of oily sludge treatment technologies will help researchers to have a good understanding of the recent developments and future research directions.