The invention discloses a novel method for purifying an arsenic chelating type immune complex. The method comprises steps as follows: S1, a chelating agent solution is prepared firstly through dissolution of a chelating agent in a solvent; S2, a proper amount of carrier protein is taken and added to a borate buffer solution, and a carrier protein solution can be prepared; S3, the prepared chelating agent solution is added to the carrier protein solution, the carrier protein solution is put in a constant-temperature water bath and stirred uniformly for constant-temperature water bathing, and amixed solution can be obtained; S4, a semipermeable membrane is homemade; S5, arsenic ions and other heteroions which are not chelated are removed through pre-purification; S6, unbound carrier proteinis removed. Part of articles are homemade in the purification process, so that the purification cost can be notably reduced, the requirements for working environments are lower, the applicable rangeis wider, the purification time is effectively shortened by use of a combined chromatographic column, and the cost is reduced to a certain extent.