Abstract: Biomass is important renewable resources, mainly containing cellulose, hemicellulose, and lignin. Hemicellulose is the second most abundant component in plant cell walls, and it can be hydrolyzed to prepare important chemicals and modified to prepare multifunctional materials. This article reviews the research progress of molecular simulation of biomass hemicellulose, including the molecular simulation study of the morphology of hemicellulose macromolecules and its binding mode to cellulose, and the molecular simulation research on the preparation of chemicals and materials from hemicellulose. It can be concluded that the interaction of hemicellulose with cellulose and lignin in the cell wall and its macromolecular morphology have significant influence on the extraction and utilization of cellulose, hemicellulose, and lignin. Molecular simulation is helpful to understand the process mechanism and has important theoretical guiding significance for the improvement of reaction efficiency. Finally, the development and application of molecular simulation in hemicellulose research are prospected. The blank areas of hemicellulose molecular simulation are pointed out, mainly including the production of bio-oil by hemicellulose liquefaction, xylose isomerization to produce xylulose, the binding interaction between hemicellulose and lignin, and other hemicellulose-based materials, which requires further exploration and research.