A preparation method of a high-performance PVDF composite ultrafiltration membrane with the surface loaded with a TiO2 thin membrane is provided. The invention is used for solving the problems of complex process, high membrane preparing cost, and difficult industrialized production existing in a conventional method for improving membrane hydrophilicity so as to improve membrane flux, anti-fouling performance and the like. The preparation method comprises the steps: 1, preparing a PVDF polymer membrane casting solution, and preparing an ultrafiltration basement membrane by an immersion-precipitation method; 2, preparing an auxiliary agent solution; 3, soaking the basement membrane in the auxiliary agent solution, taking out and swashing with water, and soaking in deionized water; 4, preparing a titania precursor solution; 5, immersing the basement membrane in the titania precursor solution, hydrolyzing a precursor, taking out and swashing with water, and thereby obtaining the high-performance ultrafiltration membrane with the surface firmly loaded with the TiO2 thin membrane. The method of the invention has the advantages of simple operation and low cost; and the obtained ultrafiltration membrane has large permeation flux, high rejection rate, strong hydrophilicity and outstanding anti-fouling performance. The preparation method is used for the membrane processing field.