In this paper,polyvinylidene fluoride (PSF) as the membrane material,to dimethylacetamide (DMAc) as solvent and lithium chloride (Licl) as additives,methanol,ethanol and glycerin bath gel,respectively,by immersion precipitation - prepared by phase inversion with different membrane composition of coagulation bath.Evaluation of microfiltration membrane device with a measured water flux and BSA rejection rate.Simultaneous measurement of membrane length and width and the porosity of wet and dry weight were calculated.Investigated the nature of coagulation bath on membrane structure and membrane properties,by regulating the composition of coagulation bath,access to the PVDF membrane with a performance than,and the formation mechanism of phase transformation were analyzed.