Abstract: To investigate the impact of the hybrid pre-ozonation and carbon nanotubes (CNTs) pre-deposition technology on fouling control, humic acid (HA) and sodium alginate (SA) were selected as model pollutants. The fouling mechanism was systematically analyzed with the transformation of normalized flux, Hermia model, conventional cake-layer fouling filtration model, and the changes of foulants' physicochemical properties. Results demonstrate that the electronegativity and hydrophilicity of HA and SA are further enhanced after pre-ozonation, and the ozone-induced micro-flocculation increases their nano-particle size. Pre-ozonation displays limited effect on membrane fouling caused by HA, as the membrane pores are completely blocked since their approaching particle size of ozonated HA and the pore size of membrane, which aggravates the fouling. Ozone can destroy the gel properties and remarkably alleviate the cake-layer fouling caused by SA. After CNTs pre-deposition on membrane with different pore size, the CNTs layer can intercept the HA and SA molecules and alleviate the membrane fouling. The denser layer forms by CNTs on the PVDF membrane with pore size of 0.45 μm, alleviates membrane fouling to the greatest extent. With a higher amount of CNTs loading, the combination of pre-ozonation and CNTs pre-deposition can effectively alleviate the membrane fouling induced by HA. As for the SA, the hybrid technology plays an outstanding role in fouling control. It effectively reduces the formation of cake layer, and prolongs the pore blocking time, and increases the transition stage from pore blocking to cake filtration as well.s