The invention specifically relates to a preparation method for a polymer anion-exchange membrane, belonging to the field of preparation of anion-exchange membranes used for fuel cells. The preparation method comprises the following steps: uniformly mixing a dicationic imidazole salt with base membrane monomers, an initiator and a cross-linking agent; then carrying out a stirring reaction under heating until a mixture becomes viscous liquid; and subjecting the mixture to polymerization in ultraviolet light so as to form the polymer anion-exchange membrane. The preparation method provided by the invention overcomes the problem that the dicationic imidazole salt is precipitated and undergoes macroscopic-phase separation in membrane preparation via conventional methods and guarantees high content of the dicationic imidazole salt and uniform film formation.