Coal power is the major force behind the flexible peaking of China's power system. Its complete phaseout is unrealistic and may cause multiple problems related to social stability. Therefore, how to guarantee a steady and orderly transition of coal power is critical. To promote coal power to transform smoothly, this study applies a modified fuzzy Decision-making Trial and Evaluation Laboratory (DEMATEL) approach to identify key influencing factors and their influence-influenced connection in Chinese coal power transition, basing on a state-owned coal-fired plant. Firstly, by surveying literatures and consulting experts, an index system of 12 main factors is identified, which includes 4 dimensions (management capability, market price, resource allocation, society environment). Then, the Interval Type-2 Fuzzy Sets (IT2FSs), Ordered Weighted Average (OWA) operator, and K-means clustering algorithm are used to optimize the approach. Six factors are judged as key influencing factors in coal power plant's transition according to the findings, among which policy, units' configuration, and market prices are included with high scores. Finally, political solutions are proposed to facilitate the efficient transition of coal plant.