The PVDF ultrafiltration membrane was modified by step in situ polymerization coupled with TiO2-PANI membrane surface modifying. It has been prepared by different oxidants, such as ammonium persulfate (APS) and ferric chloride (FeCl3). Meanwhile, application of the modified PVDF ultrafiltration membrane on treating micro-polluted surface water was studied. Turbidity removal efficiency, organic compounds and ammonia nitrogen (NH3-N) were mainly concerned. The results show that the modified PVDF UF membranes can remove 95% turbidity, UV254 higher than 50% which was increased greater than the original film. When FeCl3 was taken as oxidant with 0.03mol/L, less by-product, NH4+, was generated than APS. Thus, the ammonia nitrogen removal rate is as high as 85.2% and is 20% more than the original film.