TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The fluoric ion exchange resin is formed through copolymerization of fluoric olefin, one or more fluoric olefin monomers with functional radical and one or more fluoric olefin monomers with cross-linking site, or mixture of the copolymer; the fluoric olefin is selected from one or more of tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoropropylene and/or polyvinylidene fluoride, optimally, the fluoric olefin is selected from tetrafluoroethylene or chlorotrifluoroethylene; the fluoric olefin monomer with functional radical is selected from one or more of structure showed by the following Formulas (VI), (VII) and/or (VIII); the fluoric olefin monomer with cross-linking site is selected from one or more structure showed by the following Formulas (IX) and/or (X). The equivalent weight (EW) value of the fluoric ion exchange resin is 700-1200 mmol/g, there are 2-10 layers of membranes, and the total thickness is 10-50 mu m.a, b, v=integers between 0 and 1, but they can not be zero at the same time;d=an integer between 0 and 5;n=0 or 1;Rf1, Rf2 and Rf3=respectively selected from perfluoroalkyl or chlorofluoroalkyl;X=selected from F, Cl, Br or I;Y1, Y2, Y3=selected from SO2M, COOR3 or PO(OR4)(OR5);M=selected from Br, F, Cl, OR or NR1R2;R=selected from methyl, ethyl or propyl, H, Na, Li, K or ammonium;R1 and R2=respectively selected from H, methyl, ethyl or propyl; R3=selected from H, Na, Li, K, ammonium, methyl, ethyl or propyl;R4 and R5=respectively selected from H, Na, Li, K, ammonium, methyl, ethyl or propyl;Y4, Y5=respectively selected from Cl, Br, I or CN;a', b', c'=respectively are 0 or 1, but a'+b'+c'is not equal to 0;X1=selected from F, Cl, Br or I;n'=0 or 1; andRf4, Rf5, Rf6=respectively selected from perfluoroalkyl.Preparation: Preparation of cross-linking multilayer fluoric cross-linking ion membrane comprises utilizing pouring, extrusion, heat pressing, spin coating, casting, screen painting technologies, spray finishing or impregnating technology of solution or melt; multilayer membrane is prepared through combination between single-layer membranes, combination between single-layer membrane and multilayer membrane, or combination between multilayer membrane and multilayer membrane, or prepared by utilizing pouring, extrusion, heat pressing, spin coating, casting, screen painting technologies, spray finishing or impregnating technology of solution or melt on the prepared single-layer membrane or multilayer membrane. The step of utilizing the solution pouring, solution casting, extrusion, screen painting technologies, spin coating, spray finishing or impregnating technology is as follows: (a) scattering fluoric ion exchange resin, inorganic dopant, cross-linking agent, acid and/or free radical initiating agent into solvent to forming mixture, content of the fluoric ion exchange resin in the mixture is 1-80%, weight ratio; (b) utilizing the solution prepared in (a) to form membrane on flat plate or prepared single-layer membrane or multilayer membrane through solution casting, solution pouring, screen painting technologies, spin coating, spray finishing or impregnating technology; when forming membrane, it is necessary to perform heat treatment for 10-100 minutes under a temperature of 30-300 degrees C; and (c) cross-linking during or after membrane forming to form cross-linking structures showed by Formulas (I), (II), (III), (IV) and/or (V). Preferred Solvents: The solvent in (a) is one or more of dimethyl formamide, dimethyl acetamide, methyl formamide, dimethyl sulfoxide, N-methyl pyrolidone, hexamethyl ammonium phosphate, acetone, water, ethanol, methanol, propanol, isopropanol, glycol and/or propanetriol; when forming membrane in (b), it is necessary to perform heat treatment for 20-60 minutes at 80-250 degrees C. Preferred Method: The step of melt extrusion and heat pressing is as follows: (a) preparing proper mixtures of fluoric ion exchange resin, cross-linking agent, acid and/or free radical initiating agent according to requirement of each formulation in the multilayer cross-linking fluoric ion membrane, utilizing double screw extruder, Banbury mixer or rubber compounding mill to mix under a temperature of 200-280 degrees C; the fluoric ion exchange resin is selected from sulfuryl fluoride, sulfuryl chloride or sulfuryl bromide resin; (b) forming the mixed resin in step (1) into membrane by utilizing screw extruder or flat vulcanizing machine; (c) cross-linking during or after membrane, forming cross-linking structure shown in (I), (II), (III), (IV) and/or (V), so as to obtain single-layer membrane; and (d) combining single-layer membrane to obtain the multilayer fluoric cross-linking ion membrane. Moreover, the method of forming the cross-linking method shown in formula (I) includes heat, light, electronic radiation, plasma, X radial or free radical evocating agent, or forming cross-linking structure through heat, light, electronic radiation, plasma, X radial or free radical evocating agent with the existence of one or several cross-linking agents; where structure of the cross-linking agent is shown in the following Formula (XI): X2Rf7X3.X2 and X3=selected from Cl, Br or I; andRf7=selected from perfluoroalkyl group or chlorofluoroalkyl group.The free radical evocating agent is organic peroxide, azo evocating agent and so on, where formula of peroxide evocating agent can be expressed as Formulas (XII) and (XIII); Formula XII: R1OOR2.R1 and R2=respectively selected from the following groups arbitrarily and not limited in these groups: R1 and R2 are respectively selected from the following groups and not limited in these groups: H, alkyl of C1-C20 or aryl substituted alkyl, C1-C20 acyl, C1-C20 aroyl, C1-C20 fluoric or perfluoroalkyl or aryl substituted alkyl, C1-C20 fluoric or perfluoroacyl, C1-C20 fluoric or perfluoroaroyl; but R1 and R2 can not select H at the same time; andR3 and R4=respectively selected from the following groups arbitrarily and not limited in these groups: alkyl of C1-C20 or aryl substituted alkyl, C1-C20 fluoric or perfluoroalkyl or aryl substituted alkyl; azo evocating agent is the following but not limited in the following: azobisformamide, vazo, azobis-isobutyl cyanide, azobis-isoheptenoic cyanide, azodiisobutyric acid dimethyl ester, 1-((cyano-1-methyl ethyl)azo)methanamide, 1,1'-azo(cyclohexyl-1-cyano), 2,2'-azo(2-methyl propyl amidine)dihydrochloride, 1,1'-azobis(4-cyano-pentanoate), or 3-hydroxyl-4-nitryl benzoic acid.Forming (II), (III) cross-linking structure comprises using vikane, sulfonyl chloride, sulfuryl bromide typed resin to react with ammonia, hydrazine, organic diamine or substance releasing ammonia, hydrazine and organic diamine by chemical process; the organic diamine is alkyl of C1-C20 or fluoric alkyl diamine, the substance releasing ammonia, hydrazine and organic diamine by chemical process includes organic or inorganic acid salt of ammonia, hydrazine and organic diamine, carbamide or carbamidine. On the other hand, method of forming (IV) cross-linking structure is using chlorosulfonic acid to process so as to obtain fluoric sulfoacid resin; method of forming (V) cross-linking structure is forming fluoric sulfoacid resin at cyano site, fluoric sulfuryl fluoric resin at cyano site, sulfonic acid chloride resin at cyano site or sulfuryl bromide resin at cyano site with effect of heat or acid; the acid is strong proton acid or Lewis acid; where the strong proton acid is selected from sulfuric acid (H2SO4), CF3SO3H or phosphoric acid (H3PO4); the Lewis acid is selected from zinc chloride (ZnCl2), iron chloride (FeCl3), aluminum chloride (AlCl3), organic tin, organic antimony or organic tellurium. The free radical evocating agent is perfluoro-organic peroxide.