NOVELTY - Preparing gel polymer electrolyte of lithium ion battery, comprises (i) preparing gel liquid by mixing monomer acrylonitrile and vinyl acetate and processing emulsion polymerization, adding copolymer into solvent, and dissolving to obtain sticky gel liquid; (ii) coating by immersing a non-woven fabric supporting body into the gel liquid; (iii) initiating phase transfer on the non-woven fabric supporting body polymer film coated by the polymer in deionized water; (iv) drying the polymer film to remove residual solvent; and (v) immersing the film supported by non-woven fabric into electrolyte.    USE - The method is useful for preparing gel polymer electrolyte of lithium ion battery.    ADVANTAGE - The gel polymer electrolyte: has improved mechanical strength; is economical; has improved ionic conductivity, decomposition tension, charge-discharge circulation performance of the whole battery and the multiplying power performance, when compared with the electrolyte without supporting body; and can be used in the conventional device for preparing the liquid lithium ion battery and the production line does not need to be designed again. The method is simple, consumes less time and has high efficiency.    DETAILED DESCRIPTION - Preparing gel polymer electrolyte of lithium ion battery, comprises (i) preparing gel liquid by mixing monomer acrylonitrile and vinyl acetate and processing emulsion polymerization to obtain copolymer polyacrylonitrile-vinyl acetate, adding copolymer polyacrylonitrile-vinyl acetate and nano particle into solvent with the mass percent of 0.5-5%, where the adding amount of the nano particle is 5-20% of the mass of the polymer, and dissolving to obtain sticky gel liquid; (ii) coating by immersing a non-woven fabric supporting body into the gel liquid and taking it out after 10-20 minutes; (iii) initiating phase transfer on the non-woven fabric supporting body polymer film coated by the polymer in deionized water; (iv) drying the polymer film at 80-100 degrees C to remove residual solvent to obtain the lithium ion battery gel polymer film supported by non-woven fabric supporting body; (v) quickly immersing the lithium ion battery gel polymer film supported by the non-woven fabric supporting body into electrolyte for 1-2 hours to obtain the gel polymer electrolyte of lithium ion battery supported by the non-woven fabric supporting body. The non-woven fabric supporting body is polyethylene (PE) and/or polypropylene (PP). The solvent is at least one of acetone, N,N-dimethylformamide or tetrahydrofuran, and the nano particle is silicon dioxide, aluminum oxide, stannic oxide, titanium dioxide, lithium aluminum oxide, cerium dioxide, iron oxide, calcium oxide, calcium carbonate, barium carbonate, rare earth metal, clay and/or zeolite. An INDEPENDENT CLAIM is also included for the gel polymer electrolyte of lithium ion battery, prepared by using the above mentioned method.