Abstract: Using melt spinning technology,polyurethane/polyvinylidene fluoride(PU/PVDF) blend was spun into hollow fiber membranes with interfacial micro-voids.The miscibility of PU and PVDF was analyzed.The pore formation of the membrane was discussed,and the morphology of the membrane was also observed.Results showed that with the improvement of the miscibility of PU and PVDF,the spinnability of the blend increased,but the pore formation property decreased.The interfacial micro-voids were opened by drawing,and with the increase in draw ratio,the water flux increased,then decreased and followed by fast increasing and the aggregation of the blend also became more regular.The structure of the membrane obtained was symmetrical and there were many interfacial micro-voids on the surface of the membrane with high draw ratio.