The present invention comprises a polysulfone-based polymer and a hydrophilic polymer, an inclined asymmetric structure with an average pore diameter increases toward the inner surface from the outer surface of the pores, the content of the hydrophilic polymer in the membrane There is a 6.0 to 12.0 wt%, the porous hollow fiber ratio of content of the hydrophilic polymer content and film of the hydrophilic polymer of the outer surface is 1.20 to 1.60 to provide a filtration membrane.