In order to explore the clean fuel for iron ore powder sintering and reduce the use of coke powder，four processes are used to carbonize wood chips and prepare biochar by two carbonization processes ( i. e.，the first carbonization temperature rises to 300，350 and 400 ℃ for 30 min，respectively，and the second carbonization temperature rises to 600 ℃ for 30 min) and one carbonization ( directly heating to 600 ℃ without insulation in the middle) . At the same time，the basic properties of biochar under different processes are analyzed，and the mixed combustion characteristics of biochar and coke powder are experimentally studied by thermogravimetric method. The results show that，compared with biomass， biochar has lower volatile content and higher fixed carbon and calorific value，and the structure is denser，but the structure is looser and more porous than that of coke powder. The biochar yield of the carbonized stage is the highest，and the content of CO，CH4 and H2 in the pyrolysis gas is the highest，and the CO2 content is the lowest. Among the four carbonization processes，the ignition point，burnout temperature and peak temperature of biomass charcoal using a carbonization process are the lowest，the combustion characteristic index and average weight loss rate are the largest，the activation energy is the lowest，and the flammability is the best. Compared with coke powder，biochar-coke powder has a lower ignition point，burnout temperature and better combustion performance when combusted by biochar-coke powder. In addition，there are two main stages in the mixed combustion of biochar and coke powder: “combustion stage I”dominated by biochar combustion in the low temperature area,and“combustion stage II”with coke powder combustion in the high temperature area.