This paper discusses the theoretical basis for the assessment indicator system of eco-industry in coal mining area. Based on characteristics and development model of eco- industrial chain, the indicators from natural resources, economic, and environmental benefits and social benefits are investigated, and the assessment indicator system of eco-industry in coal mining area is described. The fuzzy synthetic judgment model for eco-industry assessment is given, and new methods of determining indicator weight by Analytical Hierarchy Process (AHP) and modified by Entropy technology is studied. In addition, fuzzy membership functions of indicators are presented. These models and methods are tested using 2010 indicator data from the Longkou Mining Area. Consequently, specific suggestions to the development of eco-industry in the Longkou Mining Area and the extension of eco-industrial chain are achieved.