Abstract:In recent years, crop remote sensing monitoring technologies have been widely applied and rapidly developed in the monitoring of food crops, cash crops, and other major crop types. These developments provide important technical support for efficient utilization of agricultural resources, agricultural production management, agricultural policy formulation and macro-level decision-making, safeguarding national food security and the supply of major agricultural products, as well as for enhancing comprehensive agricultural production capacity. Focusing on major grain, oil, cotton, and sugar crops that are closely related to national food security and the supply of important agricultural products, the research progress and applications of common key technologies for crop remote sensing monitoring were summarized. It systematically reviewed the data sources and observation approaches for crop remote sensing monitoring, followed by a synthesis of common key technologies in the retrieval of crop canopy parameters, crop area mapping and monitoring, crop growth condition monitoring, and remote sensing-based crop yield estimation. Specifically, the review covered major data sources and indicators, models, algorithms and technical methods, large-scale applications of key technologies, existing challenges, and future development trends. Finally, prospects for research and application of crop remote sensing monitoring were discussed. It showed that the development of multi-source remote sensing information (such as high-spatial and high-temporal resolution multispectral satellites, hyperspectral remote sensing, thermal infrared remote sensing, solar-induced chlorophyll fluorescence, synthetic aperture radar, unmanned aerial vehicle remote sensing), as well as machine learning, radiative transfer models, crop growth models coupled with remote sensing data assimilation methods, had significantly improved the spatial refinement, temporal continuity, quantitative parameter retrieval, and process interpretability of crop monitoring. In the future, crop remote sensing monitoring should further strengthen integrated space-air-ground collaborative observation, multimodal data fusion, mechanistic knowledge constraints, and the integration of intelligent algorithms, thereby promoting the transformation of crop remote sensing monitoring toward intelligent monitoring, standardized data products, and full-chain information services covering “monitoring-early warning-decision-making”, providing effective support for China’s national food security, the stable supply of important agricultural products, global food security, and sustainable development.