Biomass combustion device for docking boilers, heat exchangers, and heating systems, including the burner body, the carbonization machine used to generate the fuel required for combustion of the burner body, and the steam generator. The steam output pipe of the steam generator is connected to the combustion The furnace of the machine body is connected. After the biomass raw material is initially cracked by the carbonization machine, tar is precipitated, and the resulting biomass fuel has a low tar content, which effectively avoids coking in the furnace during the combustion process. At the same time, the use of steam to support combustion can not only help to eliminate coking, but also improve the fire temperature of the combustion flame, the biomass fuel rate and the calorific value. The present invention organically combines the carbonization machine, the steam generator and the burner itself to improve Traditional biomass burners have problems such as low combustion rate, easy coking, low work efficiency and unstable operation. In addition to being used for docking boilers, heat exchangers, and heating systems, the present invention can also be applied to other equipment or systems that use open flame heating, such as large thermal motors.