ln order to solve the problem of ultrafiltration membrane fouling, the types and compositions of pollutants were discussed, and the causes and influencing factors of membrane fouling were analyzed. The effects and control parameters of three pretreatment processes of coagulation, oxidation and adsorption were discussed. According to the analysis, for different water quality and membrane fouling types, the pretreatment process should be screened and the control parameters should be optimized based on the coagulation mechanism, oxidative decomposition and adsorption. In order to solve the key problems such as the decrease of membrane flux and the increase of membrane resistance, the pretreatment process should be selected according to the raw water quality conditions, the types of main pollutants and the material properties of ultrafiltration membranes. Pretreatment is of great significance in preventing the membrane pores blockage, reducing the thickness of the filter cake layer and extending the service life of the membrane, reducing energy consumption and production costs.