The invention provides a method for treating secondary waste viscose, belonging to the field of viscose. The method has the following beneficial effects: by carrying out a reaction on the secondary waste viscose and acid bath solution containing sulfuric acid and sulfates fully, the components of the secondary waste viscose are changed and cellulose is generated, and the acid concentration of theacid bath solution is reduced, the cellulose is burnt to obtain the substances harmless to the environment and the environmental treatment process is simplified after the acid concentration of the acid bath solution is reduced, so two types of wastes can be treated at the same time, thus lowering the cost and improving the working efficiency.