The invention relates to a preparation method for adsorbent for sugar liquor refining. By adopting ion exchange resin grafting a tertiary amine group [-N(CH3)2] on a styrene-divinylbenzene copolymer in a porous structure as a raw material, a swelling agent, water, p-trifluoromethyl benzaldehyde C8H5F3O and tannin C76H52O46 are added; tannin resin is fixed on amino resin through condensation reaction and a grafting method; p-trifluoromethyl benzaldehyde plays a critical role in a Mannich reaction system; tannin can be fixed on the amino resin through a bridging effect of p-trifluoromethyl benzaldehyde; a lot of phenolic hydroxyl groups on the surface of cured tannin macroporous resin not only are donors of hydrogen bonds, but also receptors of hydrogen bonds, and impurities such as phenolic compounds, iron, furfural and the like in an xylose solution can be adsorbed by virtue of a relatively strong hydrogen bond action force, so that the sugar liquor refining effect is improved.