PVDF and PES-C blend membranes are prepared via TIPS method by using DBP and DMAc as mixed diluent. Membrane structure is observed and pure water flux is tested. Waste water treatment property is also checked in MBR. Compared with PVDF membrane, the blend membrane has a thinner skin layer and a porous support layer. Pure water flux of blend membrane is twice as much as that of PVDF membrane, at the same time, the blend membrane has higher sewage flux and higher remove ratio of COD and NH4+-N. The smaller flux attenuation coefficient of blend membrane represents a better antifouling property of it.