The invention discloses preparation of a sulfonylurea molecular imprinting material with a polyion liquid as a functional monomer, and relates to polyion molecular imprinting materials. A molecular imprinting polymer material is prepared by taking 1-vinyl-3-octyl imidazole tertfluoborate as a functional monomer, glycol dimetacrylic acid ester as a cross-linking agent and dimethyl sulfoxide as a pore-foaming agent. 1-vinyl-3-octyl imidazole tertfluoborate is effectively combined with template molecules, namely triflusulfuron-methyl, through hydrogen-bond interaction; the cross-linking agent and the pore-forming agent are further added; a three-dimensional net-shaped polymer is generated through a polymerization reaction, and then template molecules are eluted; through combination site selection, recognition and memory target molecules on the molecular imprinting material, the selectivity of the material is improved, and effective extraction of sulfonylurea herbicides is achieved. Meanwhile, the prepared molecular imprinting material has the advantages of being simple to prepare, good in repeatability, low in cost, good in environment-friendliness, so that the prepared sulfonylurea herbicide molecular imprinting material with a polyion liquid as a functional monomer has application values.