The invention relates to a refinement method of a high-polymer material, particularly a method for refining a polyetherketoneketone crude product by using 2-hydroxyphosphonoacetic acid. The method comprises the following steps: stirring a certain amount of the polyetherketoneketone crude product in a dimethyl-sulfoxide-containing water solution under reflux; adding a 2-hydroxyphosphonoacetic acid water solution, stirring under reflux, cooling and filtering; and washing with a hydroxyacetic acid-formic acid mixed water solution under reflux, filtering, and drying to obtain the polyetherketoneketone pure product. By utilizing the swelling characteristic of the dimethyl sulfoxide water solution for the polyetherketoneketone, the polyetherketoneketone molecular chain closely coated on the catalyst impurities can be pulled off, so that the impurity ions are exposed and diffused into the medium. The efficient metal chelation capacity of the 2-hydroxyphosphonoacetic acid is utilized to continuously trap metal ions, thereby efficiently removing Al<3+> from the polyetherketoneketone crude product.