Abstract: A composite gel-type polymer electrolyte membrane, as a separator between the positive and the negative electrode for secondary battery, consists of crosslinked gel-type polyacrylonitrile (PAN) electrolytes, polyvinylidene fluoride (PVDF) polymers and liquid electrolytes. The crosslinked gel-type PAN electrolytes are copolymerized by acrylonitrile (AN) monomers and crosslinked monomers with two terminal acrylic acid ester function groups. The PVdF can be PVdF-co-HFP polymers containing over 80% PVdF. The liquid electrolytes are made from using nonaqueous solvents to dissolve alkaline or alkaline earth metallic salts. This invention has advantages of superior ionic conductivities and mechanical strength at high temperature, fine compatible to positive and negative electrodes and potential to be industrialized.