In oil refining enterprises, different oil refining process would produce a certain amount and quality of wastewater. Based on the tracking model of material flow analysis method, all the water process was integrated into the water balance system, and the optimization model and evaluation index system of the water supply network were established. Taking the oil refinery in China as an example, the water network model of the oil refining production process was constructed, and the minimum water consumption problem of the current water system was determined. The method was optimized and evaluated. The results showed that the fresh water consumption could be reduced by 26.90% and the sewage discharge could be reduced by 84.42% after taking the water system optimization measures. Waterenvironmental efficiency increased by 15.34%.