Abstract: Against the backdrop of the current global commitment to achieving the dual-carbon goals of carbon peaking and carbon neutrality, the question of how to effectively increase the proportion of renewable energy and reduce the reliance on traditional fossil fuels such as coal has become a key issue in the transformation of the energy strategies of countries around the world. Biomass energy, as a renewable resource with great potential, has emerged as a promising avenue with its abundant quantity, widespread availability, convenient storage and transportation. The significant coupling of biomass in coal-fired boilers can effectively reduce emissions of greenhouse gases, nitrogen oxides, sulfur oxides, and other pollutants. Additionally, due to the high volatile content, high reactivity, low ash and sulfur element in biomass, it can be used not only as a direct combustion feedstock but also a coupled fuel with coal powder combustion after gasification. Whether adopting the direct combustion coupled power generation technology or gasification coupled combustion power generation technology, the mainstream direction for the transformation of traditional thermal power plants is evident, given the minimal need for equipment upgrades and the high utilization rate of fuel resources. This paper start from the biomass resources and utilization in China, systematically reviews the current research status of biomass and the direct coupled combustion, as well as the gasification coupled combustion, with the focus on the research on emissions of pollutants, ash accumulation, slagging, and corrosion aspects. Further, we summarize the existing engineering project at home and abroad, and make an evaluation of the future development trend of this technology is evaluated. This work will provide theoretical support for the low-carbon transformation of the thermal power industry.