Grafted starch ion exchange resin (GSR) was synthesized by natural starch (RS), sodium methacrylate (SMAS) and styrene (ST). The structures of products were characterized by infrared spectrum(IR), Raman spectroscopy(RAM) and 13CNMR. When the initiator concentration was 0.056 mol/L, mole ratio of n (ammonium persulfate) : n (sodium bisulfite) = 3:1, reactant input ratios was n (RS) : n (SMAS) : n (ST) = 4:2:1, reaction temperature at 65 ℃, reaction time of 3 h, the sulfonic acid group content was up to 15.65%, the methylene blue adsorption amount was 17.98mg / g, both of which increase first and then decrease with the monomer addition amount. BET test showed that GSR has increased specific surface area than native starch which is 5.078m2/g. GSR has improved stability and higher resistance to acids, bases and enzymes. It has improved adsorption to methylene blue, Safranine T and malachite green, and reduced adsorbing differentiation for dyes with different structures, moreover, it showed a good adsorption properties under different pH conditions. The decolorization rate of GSR on mixed dye waste-water has closed to 85.08%, which increases by 91.03% in comparison with RS, and better than that of zeolite and 001×7 cation- exchange resin. After four regeneration cycles, the decolorization rate is not lower than 91.12% of the first adsorption rate. The decolorization rate of GSR resin increases with the decrease of particle size. When the particle size is 150~250μm, the GSR has relatively high decolorization, and moderate particle size that similar to synthetic resin, which is convenient for the reuse and recycling, thus conducive to the continuous operations.