Abstract: The nano calcium chloride /PVDF hybrid membrane was prepared via thermally induced phase separation, the microporous PVDF membranes morphology, retention rate, the water flux and the film strength under different content of nano calcium chloride were studied.Taking the water flux and the film strength as the response value, the optimum content of nano-particles of CaCl2, PVDF and the coagulation bath temperature were found through the response surface method.The results showed that the addition of nano calcium chloride could obviously chang the morphology of the PVDF membrane.With the increasing content of nano calcium chloride, the sponge-like holes gradually disappeared, a lot of film surface interface holes generated, the membrane flux and film strength increased, and then decreased, while its rejection rate was less affected, when the mass fraction of nanoparticle calcium chloride was 5%, the water flux and rejection rate reached a maximum.The optimum process conditions of high strength film were the content of nano calcium chloride and PVDF were respectively 4.7%, 44%, the solidification temperature was 49.5℃.Under this condition, the membrane rejection rate, the water flux and the film strength were respectively reached 75%, 174L·m- 2·h- 1and 29.8MPa.