NOVELTY - Heterocyclic polymer alkaline anion-exchange membrane with a side chain (IV), prepared by performing an active halogenation reaction on a polymer and reacting with ammonium agent in presence of a crosslinking agent, is claimed. The ammonium agent is lower amine e.g. triethylamine or dimethylethylamine, or nitrogen-containing heterocyclic compound e.g. pyrrolidine, piperazine or nitrogen-containing spiro and bridged rings. The polymer is phthalazinone biphenyl polymer (I) or its derivatives, phthalazinone terphenyl polymer (II) or its derivatives, or polyphenylene ether polymer (III).    USE - The heterocyclic polymer alkaline anion-exchange membrane is useful as functional membrane in fuel cells, secondary energy storage cells, alkali production industries, electrolytic diaphragms and other electrochemical devices.    ADVANTAGE - The alkaline anion exchange membrane: has good mechanical performance and high temperature stability, good chemical stability, and high ionic conductivity; and has convenient and simple preparation process with low cost.    DETAILED DESCRIPTION - Heterocyclic polymer alkaline anion-exchange membrane with a side chain of formula (-R-G+ OH-) (IV), prepared by performing an active halogenation reaction on a polymer and reacting with ammonium agent in the presence of a crosslinking agent, is claimed. The ammonium agent is lower amine or nitrogen-containing heterocyclic compound, where the lower amine is trimethylamine, triethylamine, diethylamine or dimethylethylamine, and the nitrogen-containing heterocyclic compound is pyrrolidine, pyrazol, pyrimidine, piperidine, (2- or 3-)morpholinyl, indole, pyrazine, piperazine, imidazole, or nitrogen-containing spiro and bridged rings of formulae (Q1)-(Q13) or their derivatives. The polymer is phthalazinone biphenyl polymer of formula (I) or its derivatives, phthalazinone terphenyl polymer of formula (II) or its derivatives, or polyphenylene ether polymer (III). (II) is polyether-ether-ketone, polyether ketone, poly(ether-ketone-ether-ketone ketone), polysulfone, polyether sulfone, polyphenylene ether sulfone, or polyaryl sulfone or its derivatives, and (III) is polyphenylene sulfide or its derivatives.    G+ = a quaternary ammonium group or a composition of more than one kind of quaternary ammonium groups including at least one of heterocyclic ammonium agent;    R = -CH2- or -CO-A-CH2-;    A = aryl e.g. phenyl or naphthyl or their derivatives, or a bond;    R7, R8 = H, 1-12C alkyl or alkoxy, 1-12C unsaturated fatty alkyl or alkoxy, aryl or aryloxy e.g. benzene, biphenyl and naphthyl;    m/(m+n) = more than 0 and not greater than 1;    n/(m+n) = not less than 0 and less than 1;    p = a positive integer;    R1-R4 = H, halo (F, Cl or Br), 1-12C saturated alkyl or alkoxy, 1-12C unsaturated fatty alkyl or alkoxy, aryl or aryloxy e.g. benzene, biphenyl and naphthyl;    Y1, Y2 = bisphenylmethanone-4,4'-di-yl, bisphenylsulfone-4,4'-di-yl, (1,4-phenylene-bisphenylmethanone)-4,4'-di-yl, cyanobenzene-2,6-di-yl or 2,2',3,3',5,5',6,6'-octafluorobiphenyl-4,4'-di-yl;    A1, A2 = biphenyl groups of formulae (T1)-(T3), (9,9-bisphenylfluorene)-4',4''-di-yl, 9H-carbazole groups of formulae (T4)-(T9), 3,3-diphenylbenzofuran-2(3H)-one group of formula (T10), 4-(biphenyl-4-yl)phthalazin-1(2H)-one group of formula (T11), naphthalen-2,6-di-yl, naphthalen-1,4-di-yl, naphthalen-1,5-di-yl, naphthalen-2,7-di-yl, naphthalen-2,5-di-yl, benzen-1,3-di-yl or benzen-1,4-di-yl;    X = -O-, -S-, -C(O)-, -SO2-, -CH2-, -C(CH3)2-, -C(CF3)2- or a bond; and    R5, R6 = H, CH3 or -CH(CH3)2.    provided that: if A1 is (T11), n = 0 and Y1 is bisphenylmethanone-4,4'-di-yl, bisphenylsulfone-4,4'-di-yl, (1,4-phenylene-bisphenylmethanone)-4,4'-di-yl, cyanobenzene-2,6-di-yl and 2,2',3,3',5,5',6,6'-octafluorobiphenyl-4,4'-di-yl in (II), then corresponding polymers are phthalazinone terphenyl structure-containing ketone, sulfone, poly(aryl ether ketone ketone), poly(ether sulfone ketone), poly(aryl ether nitrile) and fluorinated poly(aryl ether) or their respective derivatives; if n is not equal to 0 in (II), then the polymers are phthalazinone terphenyl structure-containing poly(aryl ether ketone), poly(ether sulfone), poly(aryl ether ketone ketone), poly(ether sulfone ketone), poly(aryl ether nitrile) and fluorinated poly(aryl ether) or their respective copolymers. An INDEPENDENT CLAIM is also included for preparation of the heterocyclic polymer alkaline anion-exchange membrane, comprising (i) dissolving a polymer in a solvent and performing an active halogenation reaction to obtain an active halogenated polymer, dissolving the active halogenated polymer in a solvent, adding an ammonium agent and stirring for reaction to obtain a membrane casting solution, (ii) making a membrane using membrane casting solution to obtain ammonium membrane (A), dipping the ammonium membrane (A) in an ammonium agent to perform ammonium reaction to obtain ammonium membrane (D), and (iii) soaking the obtained ammonium membrane (A) or ammonium membrane (D) in 0.01-10 mol/l of sodium hydroxide or potassium hydroxide alkali lye, performing ion exchange, taking out the membrane and washing with deionized water, and drying.