Abstract: The growing demand for renewable energy has heightened the importance of recycling biomass waste. This study aimed to explore the kinetic characteristics and potential energy value of agricultural and forestry waste, as well as their fermentation products, during pyrolysis. Three types of biomass waste—corncob, leaves, and Auricularia dregs—were selected as raw materials, and their fermented counterparts were prepared for comparative analysis. Thermogravimetric analysis (TGA) and kinetic studies were conducted to investigate the pyrolysis behavior and calculate key thermodynamic parameters, including activation energy (E) and pre-exponential factor (A). Additionally, X-ray diffraction (XRD) was employed to analyze the crystal structure and phase composition of the samples. The TGA results revealed that the pyrolysis processes of the three materials and their fermentation products were similar. Each divided into four distinct weight-loss stages. The first stage (30–120 ℃) corresponded to the evaporation of moisture, while the second stage (120–250 ℃) was attributed to the decomposition of hemicellulose. The third stage (250–520 ℃), the primary weight-loss phase, was associated with the pyrolysis of cellulose and lignin. The final stage (520–800 ℃) involved the further decomposition of residual char. Among the samples, fermented leaves exhibited the lowest activation energy (2.66 kJ/mol), indicating a lower energy barrier for the pyrolysis reaction and higher potential for energy conversion. In contrast, the pyrolysis products of fermented corncob and Auricularia dregs were more complex, suggesting the need for further investigation to optimize their utilization. XRD analysis demonstrated that all samples possessed a crystalline structure, with SiO₂ identified as the predominant phase. The fermented leaves and Auricularia dregs showed similar peak positions, indicating comparable crystal structures, while the fermented corncob exhibited distinct diffraction patterns. The changes in crystal structure were attributed to the microbial degradation of cellulose, hemicellulose, and lignin during fermentation, which altered the crystallinity and phase composition of the biomass. The findings of this study highlight the potential of fermented leaves as a promising feedstock for biomass energy and chemical industries, owing to their low activation energy and high conversion efficiency. In contrast, the pyrolysis of fermented corncob and Auricularia dregs yielded more complex products, necessitating further research to unlock their full application value. This study not only provides a theoretical foundation for understanding the pyrolysis kinetics of biomass waste but also offers practical guidance for its efficient utilization. By transforming agricultural and forestry waste into valuable energy resources, this research contributes to sustainable development, addressing both economic and ecological challenges. "In conclusion, the study underscores the importance of leveraging biomass waste as a renewable energy source. The integration of thermogravimetric analysis, kinetic modeling, and XRD characterization provides a comprehensive approach to evaluating the pyrolysis behavior and crystal structure of biomass materials. The results emphasize the potential of fermented leaves as a high-efficiency feedstock, while also identifying the need for further exploration of other biomass types. Additionally, the findings highlight the importance of optimizing pyrolysis conditions to maximize energy yield and minimize environmental impact, which could significantly enhance the scalability of biomass-based energy systems. Future studies should also focus on the economic feasibility and lifecycle assessment of biomass-to-energy processes, ensuring their sustainability and competitiveness in the global energy market. This research paves the way for innovative strategies in biomass waste management, promoting a circular economy and reducing reliance on fossil fuels.