Method for purifying perfluoroalkylpolyether

The invention belongs to the technical field of purification, relating to a method for purifying perfluoroalkylpolyether with high-viscidity. The method is characterized in that the working environment should be in accordance with the 6-grade cleaning environment regulated by the national standard GB 50073-2001. The purifying comprises the following steps: heating the perfluoroalkylpolyether; cleaning a filtering device; filtering the perfluoroalkylpolyether; and testing a solid pollution degree of the perfluoroalkylpolyether. The method has high purifying rate and low attrition rate. The pollution degree of the purified perfluoroalkylpolyether is controlled at not more than NAS 1638-0 grade, and the attrition rate of the perfluoroalkylpolyether in purifying process is not more than 10%.