A method for preparing hydroxymethylfurfural, which includes: a) mixing and dissolving triose or its derivatives and solvent 1 to obtain the first reaction mixture; b) reacting the obtained first reaction mixture with Alkaline Catalyst 1 to condense into hexose; c) mixing and dissolving the resulting hexose and solvent 2 to obtain the second reaction mixture; d) adding acid catalyst 2 to the second reaction mixture, then heating the second reaction mixture at 80˜280° C. to form the third reaction mixture including hydroxymethylfurfural; e) obtaining the hydroxymethylfurfural separating by separating from the third mixture. The method is a new synthetic way for preparing 4-hydroxymethylfurfural and 5-hydroxymethylfurfural.