Activated bentonite is a kind of inorganic adsorbent material, which is usually prepared by acid modification of bentonite. In this paper, natural bentonite was modified by sulfuric acid to acquire activated bentonite with high adsorption capacity. According to the results of single-factor experiment, the range of values of activation temperature A, activation time B, acid dosage C and liquid-solid ratio D were obtained. The removal rate of β-carotene in soybean oil was considered as the response value, and the Box-Behnken response surface method was used to optimize the adsorption performance of activated bentonite by analyzing the effects of four factors on the removal rate. The results show that the established response surface model is reliable enough to be used for the optimization of the adsorption capacity of activated bentonite. Besides, activation time and acid dosage have the greatest effect on the removal rate. However, liquid-solid ratio has no significant effect on the adsorption rate within the selected range. Finally, the predicted parameters of the optimal adsorption capacity are as follow: activation temperature 92.5 ℃, activation time 5.5 h, acid dosage 40% (mass fraction), liquid-solid ratio 4∶1, and the best adsorption rate of β-carotene can reach 97.71%.