Abstract: The aim was to study the effect of macroporous resins on the decoloring process of crude polysaccharide extracted from Morus nigra Linn and the antioxidant activity of polysaccharide before and after decoloring. The static adsorption method was used to select the best decolorization resin; the dynamic adsorption method was employed to systematically investigate the absorption process conditions; and the comparative study of antioxidant activity of crude and decolorant polysaccharide was conducted by DPPH. The results showed that resin NKA- 9 provided the best decolorizing property, and the decolorization rate was 61.8%. The optimum decoloring condition of NKA-9 was as follows: the flow rate 4.8 BV/h, the polysaccharide concentration 3.261 mg/mL, and the eluent concentration 60%. Under this condition, the decolorization rate could be maximized, and the cellular antioxidant activity of decolorant polysaccharide was enhanced after decoloring by NKA-9.