The invention provides a method for processing rhizoma arisaematis. The method comprises the following steps: taking crude rhizoma arisaematis, putting the crude rhizoma arisaematis in a closed container, adding an ethanol solution with the volume specific concentration of 65-80% to suffocate and moisten the crude rhizoma arisaematis for 36-96 hours, taking the suffocated and moistened rhizoma arisaematis out of the closed container and putting the suffocated and moistened rhizoma arisaematis in a cooking container, adding ginger juice, mixing the materials uniformly, cooking the mixture until the ginger juice is blotted, airing the rhizoma arisaematis until the rhizoma arisaematis is 40-60% dry and drying the rhizoma arisaematis to obtain the processed rhizoma arisaematis. The method has the following beneficial effects: the method of suffocating and moistening the rhizoma arisaematis is adopted, the used ethanol is less and the aim of detoxication can be achieved by using the ethanol with weight only 20-40% of the crude rhizoma arisaematis; alum is not used, so excessively absorbed Al<3+> in the residues produced by processing the auxiliary material album in pharmacopeia can be avoided from poisoning nervous systems and the like, thereby ensuring clinical use safety; meanwhile, the problem of component losses caused by long-time water soaking or boiling and the problems of mouldiness and deterioration of the rhizoma arisaematis caused by long-time water soaking in hot weather are solved; and the method can effectively ensure that the rhizoma arisaematis is safe and valid to use clinically.