The modernization of reservoir management is of great significance to the coordinated development of the region. There are many factors affecting the modernization of reservoir management, and there is a certain degree of ambiguity, randomness and uncertainty among the factors. It is difficult to evaluate the modernization of reservoir management comprehensively by traditional methods. This study first studies the connotation of reservoir management modernization under the concept of coordinated development; that is, securitization, economization, scientificalization and greenization. On this basis, a modernization evaluation system and AHP-Fuzzy evaluation model for reservoir management are constructed. Then, an empirical study is conducted with six large reservoirs in Jiangxi Province of China. The results show that the modernization level of large-scale reservoir management in Jiangxi Province is generally above the middle level, and the economic management and engineering management level of some reservoirs is relatively low, resulting in a low scientific and economic level of reservoir management, which is a key factor restricting the process of reservoir management modernization.