The invention relates to a method for purifying materials containing metal impurities, in particular to a method for removing at least one metal impurity of iron, sodium and calcium from hydrocarbon materials, which comprises that the materials containing metal impurities are mixed with flash gas (low grade gas) in a low-pressure separator of a hydrogenation unit to obtain the materials with a higher impurity removal rate by a fixed bed layer of filtering materials, absorbent or catalyst. Compared with the prior art, the method in the invention has mild operation conditions and high impurity removal rate, and can be used in processing various materials containing metal impurities.