As the sole carbonaceous renewable energy source, biomass is distinguished by its abundant yield, widespread distribution, and carbon neutrality. It is integral to the achievement of zero and negative carbon production via conventional carbonaceous pellet technology. This study introduces a cradle-to-gate life cycle assessment methodology for biomass preparation in carbonaceous pellets. We prepare high-quality biochar through a process combining hydrothermal carbonization and pyrolytic carbonization. Biomass high molecular weight extracts are obtained via organic pyrolytic extraction, while biomass high-temperature binders result from the modification and treatment of biochar. Biomass carbonaceous pellets are then formed using hot press technology. The ReCiPe model facilitates a comprehensive life cycle assessment of biomass carbonaceous pellets used in blast furnace production. The study leverages two comprehensive evaluation indicators - renewability, and environmental performance - to enhance the environmental performance of the process system and to maximize energy-saving and emission reduction potential.