Abstract: Circulating fluidized bed (CFB) combustion is regarded as one of the most potential technologies for large-scale development and utilization of biomass energy in the future. This article presents a comprehensive overview of the challenges faced by biomass-fired CFB boilers including fouling and corrosion on heating surfaces, agglomeration of bed materials, low combustion efficiency, and high NO_x emissions. The corresponding solutions using active additives are discussed. For instance, the use of silica-aluminum-based, sulfur-based, calcium-based, and phosphorus-based additives, which form high-melting-point salts or reduce Cl content, effectively alleviating fouling and corrosion on heating surfaces. The introduction of oxygen carrier aided combustion technology shows promise in improving the uniformity of gas distribution within the furnace and enhancing combustion efficiency by replacing the oxygen reduction cycle reaction of bed materials. Furthermore, introducing iron-based or reducing agents in the combustion process can suppress the conversion of nitrogen precursors to NO_x or reduce the presence of already formed NO_x, thereby reducing the original emissions of NO_x. Future research on additives should focus on mechanistic analysis, standardization, engineering scaling, and solid waste resource utilization, aiming to achieve clean and efficient utilization of biomass.