NOVELTY - A fiber reinforced crosslinked fluorine ion membrane has crosslinked lattice construction having fluorine ion exchange resin, and is added with reinforcing fiber. The crosslinked lattice construction has fluoro-carbon chain as main chain, functional group as lateral group, and fluoro-alkyl chain or fluoro-alkoxy chain as crosslinking bridge. The fluorine ion exchange resin is copolymerized from fluoro-olefin, fluoro-alkene monomer having functional group and/or fluoro-alkene monomer having crosslinking site.    USE - A fiber reinforced crosslinked fluorine ion membrane.    ADVANTAGE - The fluorine ion exchange membrane has high proton electric conductivity and good mechanical property.    DETAILED DESCRIPTION - A fiber reinforced crosslinked fluorine ion membrane has crosslinked lattice construction having fluorine ion exchange resin having equivalent value of 600-1300, and is added with reinforcing fiber having electrical conductivity of 40-150 ms/cm and tensile-strength is 10-60 MPa. The crosslinked lattice construction has fluoro-carbon chain as main chain and functional group as lateral group and fluoro-alkyl chain or fluoro-oxyalkyl chain as crosslinking bridge, and is of formula (I). The fluorine ion exchange resin is copolymerized from fluoro-olefin, fluoro-alkene monomer having functional group and/or fluoro-alkene monomer having crosslinking site. The fluoro-olefin is trifluoroethylene, hexafluoropropylene and/or vinylidene fluoride, or preferably tetrafluoroethylene and chlorotrifluoroethylene. The fluoro-alkene monomer having functional group is of formula Y'1(CF2)a(CFRf1)b(CFRf2)c-O(C(CF2-X)FCF2O)n-CF=CF2, Rf3CF=CF(CF2)dY'2, or F2C=CFOCF2CFOCF2CF2Y'3. The fluoro-alkene monomer having crosslinking site is of formula F2C=CFRf4Y'4 or Y'5(CF2)a'(CFRf5)b'(CFRf6)c'O(C(CF2X1)FCF2O)n'-CF=CF2.    G1=CF2 or O;    G2=CF2 or O;    Rf=2-10C perfluoro-carbon chain or chloroperfluoro-carbon chain;    a, b, c=0 or 1;    d=0-5;    n=0 or 1;    Rf1, Rf2 and Rf3=perfluoro-alkyl and chlorofluoro-alkyl, preferably 1-10C perfluoro-alkyl and chlorofluoro-alkyl;    X=F, Cl, Br or I;    Y'1, Y'2, Y'3=SO2M, COOR3 and PO(OR4)(OR5);    M=F, Cl, OR and NR1R2;    R=Me, Et, propyl, H, Na, Li, K and ammonium;    R1, R2=H, Me, Et, or propyl;    R3=H, Na, Li, K, ammonium, Me, Et or propyl;    R4 and R5=Na, Li, K, NH3, Me, Et or propyl;    Y'4, Y'5=Cl, Br, I and CN;    a', b', c'=0 or 1;    X1=F, Cl, Br or I;    n'=0 or 1; and    Rf4, Rf5, and Rf6=perfluoro-alkyl or chlorofluoro-alkyl.    Provided that a, b and c are not 0 at the same time; and a'+b'+c'is not 0. An INDEPENDENT CLAIM is included for a method for preparing fiber reinforced crosslinked fluorine ion membrane, comprising preparing the film by using pouring, extruding, hot pressing, casting, screen printing technology, spin coating, spraying or dipping a solution or fused mass, and forming the crosslinking structure during the film forming process or after the process of film forming.