China has implemented the “2 + 26 Cities” policy for the air pollution collaborative supervision in the Beijing-Tianjin-Hebei region, it is necessary to conduct an effectiveness assessment of Beijing-Tianjin-Hebei air pollution prevention and control (APPC). Therefore, this paper proposes a complete evaluation model for Beijing-Tianjin-Hebei APPC to solve this problem and help decision makers (DMs) reasonably allocate limited resources. First of all, we establish an index system which consists of four parts: supervisory capacity, environmental effects, social effects and economic effects. Second, triangle intuitionistic fuzzy number (TIFN) is applied to describe the index data to better adapt the actual situation. Third, combining Decision Making Trial and Evaluation Laboratory (DEMATEL) with the entropy methods, the approach is utilized to calculate the index weights. Fourth, considering DMs' evaluation greyscale, grey fuzzy synthetic evaluation eliminates the defects caused by subjective preferences to a certain extent, which makes the evaluation results more reasonable. Fifth, sensitivity analysis and comparative analysis are performed to verify the reliability of evaluation results. Finally, the effectiveness assessment results show the overall Beijing-Tianjin-Hebei APPC is good, and we put forward some policy implications to further improve Beijing-Tianjin-Hebei APPC level.