Water quality management plays a very important role in fish life and aquatic product quality. The paper firstly selects the index system and confirm the weight of each of the water quality factors dependent on the fish tolerance to the factors of water quality integrated with the result of the expert questionnaire by the Delphi method with the Water Quality Standard, then constructs the fuzzy evaluation model of the multiplex water quality parameter and classifies the standard of water quality into five classes of standard. At last the paper give an experimental model based on the monitored datum in North China. It shows that it can evaluate the water quality integrative and provide the degree of membership that the water quality belongs to all the standards.