The problem of colority control of printing and dyeing wastewater has become a technical problem that plagues related companies. Bentonite is an adsorbent with excellent properties. Modification of bentonite with environmentally friendly substances can improve its decolorization performance. In this experiment, the simulated printing and dyeing wastewater was taken as the control object, and the bentonite was modified with environmentally friendly materials such as sodium carboxymethyl cellulose (CMC) and lignin to prepare a new modified bentonite; then the modified bentonite was used to adsorb the simulated wastewater to reduce the water colority and COD; finally the relevant design of the adsorption process was made. Results indicate that Mlignin: MCMC: Moriginal bentonite = 1: 2: 97 had the optimum treatment effect, the optimum modification temperature was 30℃ and the modification time was 4 h; the optimum conditions for the adsorption process were: pH = 5, temperature = 30℃, reaction time = 60 min, dosage = 0.05 g of modified bentonite/mL simulated dye solution. The final removal rate of colority and COD reached 95.0% and 98.2%, respectively. Compared with the original bentonite, this new modified bentonite has greater adsorption capacity and thus has greater application value.