Poly(vinylidene chloride-co-vinyl chloride) (P(VDC-co-VC) membranes were prepared by non-solvent-induced phase separation and adjusted by adding water-soluble polyethylene glycol (PEG) and water-insoluble silicon dioxide (SiO2) hydrophilic nanoparticles. The structure of pores and antifouling performance were investigated to illustrate the effect of these nanoparticles. The cross section of the P(VDC-co-VC) membrane exhibited more macropores and the typical finger-like pores turned into more vertically interconnected ones with increasing PEG content, while the number and size of finger-like pores became less with increasing SiO2 content. Considering the filtration and antifouling experiments, the presence of hydrophilic PEG and SiO2 nanoparticles in the P(VDC-co-VC) polymer matrix improved the membrane performance in terms of high flux, high BSA rejection ratio, and fouling resistance.