Using carbon-neutral from biomass is a promising solution to achieve carbon neutrality in pulverized coal injection (PCI) technology in an ironmaking blast furnace (BF). In this paper, a 3D CFD model, including the whole region of lance-blowpipe-tuyere-raceway surrounding coke bed, is improved to describe the in-furnace phenomena related to biochar injection under industrial-scale BF conditions. The factors such as particle shape, carbonization temperature, and coal blending are considered to determine the influence on flow and thermochemical behaviors of biochar particles. The results show that, in comparison to spherical particles, the cylindrical particles show a slower gas conversion rate and smaller burnout as a result of the shorter traveling time in the raceway; High carbonization temperature decreases the burnout of biochar in the raceway. From the perspective of the economy, BC-773 has an appropriate ratio of volatile matter (VM) to fixed carbon, which burns more fully and releases a large amount of heat in a limited time, and has the potential to better replace PCI coals in BF practice. The overall gas temperature and burnout of the biochar/coal blend show a non-additivity, indicating there is a synergistic effect during the co-combustion process. This model provides an effective way for understanding and optimizing biomass injection technology in BF practice.