The invention discloses a method for processing acidic wastewater and alkaline wastewater of the viscose fiber industry, and belongs to the field of wastewater processing method. The method comprisesan acid wastewater processing method and an alkaline wastewater processing method. Acids, alkalis, and semi-fibers can be maximally recovered from wastewater. After concentration, acids and alkalis can be returned to the production line. Semi-fibers can be used as a byproduct for sale. The production cost is reduced, and the benefits are increased for enterprises. Salts in wastewater are convertedinto acids, alkalis, and water, resources are recovered and utilized, the problem that waste sodium sulfate cannot be recovered is solved, the amount of discharged solid wastes is reduced, the provided method is applied to viscose fiber production, no wastewater or waste is discharged during the whole technical process, wastewater is recovered and reutilized in the forms of water, acids, alkalis,and semi-fibers, the organic substances are removed through a biochemical method, and the method is simple, green, and environmentally friendly and has a good industrial application prospect.