Heavy metal pollution in soil seriously threatens agricultural safety. In recent years，as a new material for soil heavy metal pollution remediation，biochar has attracted the attention of many scholars. How to strengthen the adsorption capacity of biochar through modification methods and improve the safety，efficiency，and environmental friendliness of biochar has been a research hotspot in recent years. The basic characteristics of biochar，the raw material sources of modified biochar，common modification methods，and the mechanism of adsorption and immobilization of heavy metals were reviewed，and the function and application of modified biochar prospected，which could provide a theoretical basis for the screening of soil heavy metal remediation materials.