This study selected ethylene-octene copolymer (POE) as polypropylene (PP) blend toughening modified material to prepare PP/POE hollow fiber membrane by thermally induced phase separation to study the effect of POE content on membrane properties. The results showed that the optimal addition of POE was 15%, the water contact angle of the blend membrane was increased by 8.5%, the average pore size was increased by 24.83%, and the flux of vacuum membrane distillation (VMD) increased from 8.36 kg·m-2·h-1 to 12.60 kg·m-2·h-1, an increase of 50.72%; the tensile strength of the membrane increased by 12.82%, and the maximum elongation increased by 51.89%. In this work, ethylene-octene copolymer (POE) was used as toughening modification material to prepare PP/POE co-blend hollow fiber membrane by thermally induced phase separation. The effect of POE content on membrane properties and performance was investigated. Under optimum condition ( 15%(wt) POE ), the water contact angle, the average pore size, the flux, the tensile strength, and elongation were improved 8.5%, 24.83%, 50.72%, 12.82%, and 51.89%, respectively. The flux of vacuum membrane distillation (VMD) increased from 8.36 kg·m-2·h-1 to 12.60 kg·m-2·h-1.