Abstract: As an important carbon solid material, the biochar is well-known for its large raw materials, low costs and good properties. It has been widely applied in the fields of soil improvement and environmental remediation in recent years. This paper mainly summarized and analyzed the effects of different raw materials and reaction conditions on the properties of the generated biochar, and the critical roles of biochar in enhancing electron transfer and catalytic performance. The results indicated that the raw materials and pyrolysis parameters (pyrolysis temperature, reaction time and heating rate, etc.) were closely related to the biochar properties, and slow pyrolysis at high temperature was more beneficial to the biochar production rate and properties compared with fast pyrolysis. Through chemical or physical modification, the specific surface area, catalytic properties and adsorption ability of biochar could be altered. Further analysis demonstrated that the biochar contained large amounts of surface oxygen-containing functional groups (OFGs) and persistent free radicals (PFRs). These characteristics were associated with the excellent redox properties of biochar, which contributed to the enhancement of electron transfer and catalytic activity, and exhibited countless application in resource recovery and pollutant degradation. Finally, further improvement of biochar properties, the potential influencing factors for environmental remediation performance as well as underlying mechanisms, and the economic benefits (i.e. the recovery and reutilization possibilities) were prospected. These will provide insightful guidance for the large application of biochar in the environment, which are of great scientific value and practical significance.