TECHNOLOGY FOCUS - POLYMERS - Preparation: The preparation method of the gel polymer electrolyte with semi-interpenetrating network structure comprises: (a) mixing the acrylonitrile monomer with methyl glycidyl acrylate and dissolving in N,N-dimethyl methanamide solvent at room temperature to prepare the mixed monomer solution with the concentration of 0.1-1.0 g/ml; where the mass ratio of acrylonitrile to methyl glycidyl acrylate is 1:0.5-1:8; adding initiator benzoperoxide in the solution; where the amount of the benzoperoxide used is 0.2-2% of the mixed monomer; stirring the mixture until the benzoperoxide is completely dissolved; reacting the solution for 4-10 hours at 60-90 degrees C under the protection of nitrogen or argon to obtain a mixture; precipitating the mixture and dissolving it with acetone; repeating the process; filtering the precipitate and drying it until the constant weight is obtained to obtain the copolymer; (b) stirring the solution at the room temperature; dissolving the copolymer and the polyethylene oxide obtained in (a) in accetonitrile solution to prepare the solution with concentration of 0.005-0.02 g/ml; where the mass ratio of the copolymer to the polyethylene oxide is 0.25-4:1; (c) adding the cross-linking agent diethylenetriamine in the solution prepared in (b); where the amount of the diethylenetriamine used is 8-20%; uniformly stirring and mixing the solution; and reacting it for 2-10 hours at 60-90 degrees C; (d) pouring the solution prepared in (c) on a polyfluortetraethylene plate to form a film; continuing the reaction for 4-20 hours at 60-90 degrees C after the solvent is volatized at the room temperature to obtain the cross-linked polymer film; and (e) dipping the cross-linked polymer film prepared in (d) in the electrolyte solution to adsorb the electrolyte; taking it out, and placing it in a drier filled with nitrogen atmosphere to obtain the gel polymer electrolyte film with semi-interpenetrating network structure. Preferred Components: The cross-linking agent is diethylenetriamine. Preferred Process: The 1 mol/L hexafluoro lithium phosphate carbonate electrolyte is formed by mixing methyl carbonate, diethyl carbonate, and ethylene carbonate based on the mass ratio of 1:1:1.