A method for refining high-purity acetylacetone comprises procedures of devolatiligation, deacidification and deanhydride to coarse acetylacetone which later on enters a refining tower T1. The method is characterized in that the refining tower T1 is a pressure relief refining tower, the high-purity acetylacetone is extracted from the upper side line of the rectification section in liquid phase, acetone generated by the decomposition of acetylacetone and low-boiling mixed components, such as isopropenyl acetate, which are not completely removed due to instability of the initial stage of the process, are collected at the top of the tower, returned to a coarse acetylacetone groove V1, placed in the refining tower T1 after the procedures of devolatiligation, deacidification and deanhydride, and the tower kettle uses high-boiling components. The invention has the advantages that the refining tower T1 has the function of removing a small mount of low-boiling components because of liquid phase side line discharge way thereof, meanwhile, the acetone and isopropenyl acetate obtained from the top of the tower can be recycled, and the tower kettle uses high-boiling components, so that the whole rectification section is easy to control, flexible in operation, high in purity of the finished products, and stable in mass content of 99.9%.