The construction of new-type power system is the basis for achieving China's dual-carbon goal, and integrated energy service is an important way to ensure the sustainable operation of the new-type power system. At present, the development of integrated energy service in China is still in its infancy, and the primary issue has been how to tap the market's potential. However, most of the existing studies are from the perspective of energy service providers, and there are few studies on the market potential of integrated energy services, and there is a lack of effective evaluation systems and evaluation methods, which makes it difficult to plan and layout integrated energy services from the macrolevel. Therefore, a comprehensive assessment model for the market potential of integrated energy service at the provincial level in China is proposed in this paper. First, an evaluation index system of provincial integrated energy service market potentials is constructed from four aspects: market scale, economic efficiency, energy efficiency improvement, and environmental protection. Second, the evaluation model is constructed with the entropy weight method and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. At last, the provincial market potentials of integrated energy service in China are evaluated and analyzed from the perspectives of gaps, strengths, and weaknesses, and policy suggestions are proposed to develop integrated energy service accordingly. The results show that the proposed assessment model of the provincial market potentials of integrated energy service is of practical significance to provide decision-making support for the development of integrated energy service and is conducive to promoting the sustainable development of the power system.