The corn straw was used as raw material to prepare the biochar adsorbent at 300℃、400℃ and 500℃,which were named BC300,BC400 and BC500. The adsorption capacity of corn straw biochar prepared at three temperatures was BC500＞BC400＞BC300. In addition,the initial concentration of ethyl paraben, adsorption temperature and time can affect the adsorption effect. When the initial concentration of ethyl paraben was 20 mg/L at 45℃, the removal rate of ethyl paraben reached 99.5% after BC500 adsorption. The results showed that the optimum conditions for the preparation of biochar adsorbent from corn straw for the removal of ethyl paraben were obtained, which can provide theoretical basis for the application of corn straw in the removal of organic pollutants such as ethyl paraben.