With the increasing requirement of water environment and the enlargement of government investment, a comprehensive improvement of water environment takes shape to some extent, but no evaluation index system for the comprehensive improvement of water environment is proposed. 17 indexes are selected from aspects of water improvement, landscape, ecology, function and social people's livelihood to establish an evaluation index system. Based on the basic thoughts of game theory equilibrium and coordination, AHP is used to determine the subjective weight and entropic law is applied to confirm the objective weight. The comprehensive weight is thus obtained through the combined empowerment. A comprehensive improvement evaluation model for water environment based on the combined empowerment of game theory is constructed and evaluated by using the relevant data of comprehensive improvement effect for water environment in Xuancheng City in 2015-2017, showing that the comprehensive improvement evaluation grade for water environment in Xuancheng City in 2015 belongs to medium-grade and that of 2016 and 2017 is within high-grade. The comprehensive evaluation on the upgrade, indicates that the improvement effect is constant, and that the evaluation index system provide a basis for evaluating and inspecting the comprehensive improvement of water environment in other cities.