Abstract: To address the growing pressure of carbon emissions in the coal-fired power sector, co-firing biomass with coal has emerged as a pivotal strategy for facilitating the low-carbon transition of coal-based power generation. A comprehensive understanding of the reaction mechanisms involved in the thermochemical conversion of coal and biomass is crucial for optimizing blending ratios and developing effective pollutant control strategies. A systematic review of recent advancements in this field based on Reactive Force Field Molecular Dynamics (ReaxFF MD) simulations is presented, with a focus on key aspects including model construction, identification of pyrolysis and combustion mechanisms, elucidation of pollutant formation pathways, and characterization of synergistic reaction behaviors. The construction strategies and applicability of representative structural models for coal and biomass are compared, the compatibility between different molecular configurations and ReaxFF parameter sets is evaluated, and the influence of model physical realism on simulation outcomes is highlighted. It further outlines the precursor species, radical evolution characteristics, and reaction pathways associated with the formation of major pollutants such as CO, CO₂, and NO_x during pyrolysis and combustion processes. In addition, the review analyzes cross-linking interactions, nonlinear reaction dynamics, and the effects of blending ratio variations on pollutant emissions in co-pyrolysis and co-firing systems. On this basis, the core challenges currently facing the field are summarized, including the limited automation of reaction pathway extraction, insufficient force field accuracy, mismatches between simulation timescales and real-world processes, and the lack of a clear mapping mechanism between macroscopic and microscopic parameters. Emerging strategies such as multiscale modeling, machine learning-assisted prediction, and GPU-accelerated parallel computing are also discussed in the context of their potential to enhance simulation capabilities for coal-biomass thermochemical conversion. This review provides theoretical support for elucidating the microscopic mechanisms of complex carbon-biomass interactions and offers methodological guidance and data-driven insights for the optimization of low-carbon, clean combustion technologies and precision pollutant control.