The hollow fiber UF membrane system is used for removing pollutants from drinking water. The experimental results show the filtration flux steadily increases with the working pressure in the range of the working pressure lower than 0.2MPa; the filtration flux decreases with the concentration of the raw water at the constant working pressure. The lower the organic substance of raw water is the higher the filtration flux is. Linear regression method is applied to the experimental data, and the UF membrane flux model is presented. Meanwhile the model can be used to design UF process for similar liquid mixture system.