Poly(vinylidene fluoride) (PVDF)perfluorosulfonic acid (PFSA) hollow fiber blend membranes were prepared by wet-spinning method. The effects of the heat-treatment temperature and time on the morphology, permeation performance and mechanical properties of the membranes were investigated. The results show that upon increasing the heattreatment temperature the retention rate reaches a maximum of 95.0% for PEG4000 at 80 °C while the flux shows a minimum of 231 L/(m2·h·MPa) for pure water at the same heat-treatment temperature. The appropriate heat-treatment time was 15 min for heat-treatment at 70 ℃. The morphology of the membranes was changed by heattreatment as examined by scanning electronic microscopy (SEM). The hollow fiber membranes are shrank after the heat-treatment, and the axial shrinkage ratio of the membrane is smaller than the radial one. The elongation at break declines after heat-treatment. The Young′s modulus and the break strength of the hollow fiber membranes closely correlate to the membrane structure after heat-treatment. The PVDFPFSA hollow fiber blend membranes heat-treated for 15 min at 70 °C have a cut-off molecular weight of 4 000 and flux of 261 L/(m2·h·MPa) for pure water.