The invention discloses a method for purifying epsilon-PL (epsilon-polylysine). The method comprises steps as follows: a crude epsilon-PL product with the mass concentration being 75% or above is added to deionized water, an epsilon-PL aqueous solution with the mass concentration being 30%-50% is prepared, an organic solvent with the final volume concentration being 1%-10% is added to the aqueous solution, the mixture is subjected to a heating reflux reaction for 2 h, then slowly cooled to subzero 5 DEG C, stirred for crystallization and filtered, a filter cake a is obtained and dried, and epsilon-PL is obtained. With the adoption of the method, high-purity epsilon-PL (with the purity higher than 99.5%) can be obtained, PL products lost in the technology can be recycled, and high-purity epsilon-PL solids can be obtained after vacuum drying, are convenient to store and transport and can be better applied to fields of cosmetics, medicines and the like.