Abstract: Biochar has the advantages of high carbon content, large specific surface area, well-developed pore structure and good adsorption performance. It is widely used in the fields of soil quality improvement, environmental pollution remediation, carbon sequestration and emission reduction. In view of the practical problems such as low volume density of biochar itself, difficulty in solid-liquid separation, and urgent need to further improve its long-term effectiveness and stability, the biochar composites with higher remediation efficiency for polluted environment were prepared by combining biochar with metal materials, photocatalysts and clay minerals, which attracted much attention. Through a systematic review of the preparation methods and environmental pollution control applications of biochar-based composite materials, and the removal mechanism of organic pollutants in the environment was analyzed, and the future research and development trend of biochar materials was put forward, so as to provide new ideas for the preparation and practical application of high-efficiency biochar composite materials.