With interval numbers without probability distribution introduced to represent the magnitude of uncertainty influence, the economic benefit, water supply and demand efficiency and COD emission are selected to form the economic, social and environmental objective optimization functions respectively. Thus, the inexact fuzzy multi-objective programming(IFMOP)allocation model of Yuhuan City is established and its uncertainty solution sets are calculated. The results indicate that the calculation results of IFMOP allocation model can realize the coordinated and efficient utilization of regional water in both terms of quantity and quality and the balanced development of society, economy and ecosystem in Yuhuan City. With 75% inflow rate guaranteed, the uncertainty range of total water allocation for each industry is 143. 75—151. 54 million m³. IFMOP water resources allocation model can fully utilize all kinds of data information for water resources allocation under the condition of insufficient information, so as to better meet the dynamic management demands when allocating water resources for various industries.