The invention discloses a high-efficiency adsorbent and application of the high-efficiency adsorbent in heavy metal wastewater. The high-efficiency adsorbent is composed of the following ingredients (by weight): 60-90 parts of recyclable modified activated carbon composition and 9-18 parts of a modified waste crop adsorbent. The high-efficiency adsorbent has high removal rate of lead, zinc and manganese in spent liquor, and the removal rates respectively reach up to 87.7%, 95.9% and 78.4%. The high-efficiency adsorbent provided by the invention has a good treatment effect on heavy metal wastewater.