NOVELTY - A porous gel polymer electrolyte membrane comprises (mass%): polyvinylidene fluoride (33-54), acrylonitrile-methacrylic acid polyethylene glycol monomethyl ether ester multipolymer (3-15), and 1M lithium phosphorus hexafluoride (LiPF6) carbonic ester electrolyte (43-52), to make a total of 100 mass%. The thickness of the membrane is 50-100 mu m.    USE - For use in polymer lithium ion battery.    ADVANTAGE - The preparation of membrane simple; and has no pollution to the environment. The membranous property of the polymer is good; and the membrane has high strength. The ionic conduction rate of porous gel polymer electrolyte membrane in normal temperature can reach 1.674x 1/1000/Scm. The electro-chemical stable window can reach 4.6 V.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method of preparing the porous gel polymer electrolyte membrane comprising mixing methacrylic acid polyethyleneglycol monomethyl ether ester multipolymer and acrylonitrile in ethanol solvent at 1:1-1:2.2 ratio, to prepare blending monomer solution (0.3 g/ml); adding initiator azodiisobutyronitrile (0.7% of the blending monomer); after stirring until fully dissolved, putting in nitrogen or argon, and obtaining semi-transparent viscous liquid after reacting at 70-80degrees C; removing ethanol solvent through evaporation, after which obtaining acrylonitrile-methacrylic acid polyethyleneglycol monomethyl ether ester multipolymer through drying; mixing acrylonitrile-methacrylic acid polyethyleneglycol monomethyl ether ester multipolymer and polyvinylidene fluoride in N,N-dimethyl acetamide solvent to prepare polymer solution (0.15-0.2 g/ml) after mixing and stirring at 50degrees C; cooling the polymer solution to normal temperature and coating it on glass plate; then immersing in ion-removing water to obtain porous membrane, which is immersed into 1M lithium phosphorus hexafluoride (LiPF6) carbonic ester electrolyte after being dried; and obtaining porous gel polymer electrolyte membrane after absorbing and gelation. 1M LiPF6 carbonic ester electrolyte is formed by mixing dimethyl carbonate, diethyl carbonate, and ethylene carbonate according to the ratio of 1:1:1.