The invention discloses a preparation method and application of an azacycle compound functionalized ion exchange material. The preparation method of the ion exchange material comprises that chloromethylated propylene-styrene copolymer and/or chloromethylated styrene-divinylbenzene copolymer are soaked in a solution containing an azacycle functional monomer and are subjected to a substitution reaction, and the reaction product is dried to obtain the product. The method has the advantages of simple process, low cost, and mild reaction conditions; the prepared ion exchange material can be applied in selective recovery of selenium in selenium-containing wastewater, has the characteristics of high recovery rate and less environmental pollution; and moreover, the azacycle compound functionalized ion exchange material can be recycled and reused and has low use cost.