<p>Crop straw is a kind of renewable resource with great application potential, which has the characteristics of a wide source, abundant reserves and low price. Using straw as a raw material and a hydrothermal process to prepare high-function carbon-based material, it is an economic and green way to promote straw resource utilization. In this article, the influencing factors in the preparation process of straw hydrothermal carbon were reviewed. The influences of process parameters such as straw carbon source, hydrothermal time, hydrothermal temperature and solid–liquid ratio on the structural properties of hydrothermal carbon were emphasized. The regulation of the morphology and structure of carbon by activators such as KOH and KMnO₄ were analysed. At the same time, the application of straw-based hydrothermal carbon in the field of environmental pollution control, catalysis and electrochemistry is summarized. Finally, it is pointed out that the future research should focus on the structure control method, green activation technology of straw-based hydrothermal carbon and the preparation of hydrothermal carbon from mixed straw, and further improve the stability of the porous structure of the hydrothermal carbon and the interference-free in the practical application environment, so as to realize the commercial application of straw-based hydrothermal carbon.</p>