Abstract: In order to explore the role of biomass-based fuels and chemicals in achieving energy security and the dual-carbon goals, by establishing models for energy efficiency, carbon emissions, and characteristics of energy and material consumption, using biological straw as the source material, and combining with actual project cases, through the carbon emission factor method and adopting the "cradle-to-gate" accounting boundary, integrating direct and indirect processes, three technical routes, namely ethanol production via saccharification and fermentation, methanol production via gasification, and methanol co-production with olefins, were analyzed. The energy efficiency, carbon emissions, energy consumption, and material consumption characteristics of each process were quantitatively evaluated, and optimization strategies were proposed. The findings indicate that the energy efficiency of biomass-derived methanol and its olefin co-production has approached that of traditional fossil-based processes. The low efficiency of the saccharification and fermentation process is primarily constrained by the difficulty of lignin hydrolysis. Biomass gasification-based methanol production and olefin co-production exhibit significant negative carbon effects, achieved through biomass carbon cycling and carbon capture. The saccharification and fermentation process can significantly reduce carbon emissions with 100% green electricity substitution. Carbon emissions mainly originate from raw material transportation, electricity consumption, and auxiliary material production, which can be mitigated through energy structure optimization, carbon capture utilization, and process integration. The resource consumption per unit product is highly influenced by raw material costs and transportation radius, making rational planning of production scale and transportation radius critical to enhancing competitiveness. Future research should refine carbon emission accounting methods, strengthen dynamic analysis of market and policy factors, and promote process improvement and innovation to enable large-scale industrial application of biomass energy.