U(VI) of the acid leaching uranium-containing wastewater was adsorbed by modified CMC polymer. The result showed that the grafting rate was found to be 68% on the conditions, i.e. temperature 70~80°C, monomers quality concentration 30~35%, Carboxy methyl cellulose and acrylic acid mass ratio of 10:2.5, contact time 3.5~4h. The uranium adsorption capacity of modified CMC was studied and compared with unmodified CMC. The results also revealed that U(VI) ions uptake rate was rather slow, with 75% of the total amount occurring in the first 60min for Modified CMC Polymer. the optimum experimental conditions were CMC quality concentration 0.10g/L, temperature 25°C, pH 5.0, contact time 100min; under the optimal conditions, the removal of U(VI) was 97.1% and 21% higher than unmodified CMC.