Three kinds of modified bentonite adsorbent were made by use of sulfuric acid, hydrochloric acid, and phosphoric acid. The effects of the modified bentonite dosage, initial ion concentration, pH value of solution, temperature and stirring time on the removal rate of copper ions were studied. The results showed that the adsorption rate of copper was 99%, 96%, 92% respectively, by using of bentonite adsorbent modified with sulfuric acid, hydrochloric acid and phosphoric acid reached at the condition of initial concentration of copper ion of 3 mg/L, acid modified bentonite addition amount of 2.5 g/L, pH 12, temperature of solution 20 ℃, stirring time of 15 min.