Advanced Geosynchronous Radiation Imager (AGRI) mounted on FY-4A significantly improved both temporal and spatial resolution compared with Visible and Infrared Spin-Scan Radiometer (VISSR) mounted on the Chinese first-generation geostationary meteorological satellite Fengyun-2. Based on FY-4A AGRI imager Infrared Difference Dust Index(IDDI) and a new improved day-night sand-dust remote sensing algorithm, this paper carries out continuous remote sensing monitoring of dust processes in the northern China and systematically analyzes the characteristics and affected areas of three typical sandstorms in 2021. The total impact area of the three typical sand-dust processes in the northern provinces of China reaches a minimum of more than 2.6 million square kilometres and a maximum of more than 3 million square kilometres. The dust storm from April 14 to 17 affected the largest area. The result shows that in 2021, the areas with high sand and dust occurrences were in the southern Xinjiang, north of the Hexi Corridor in Gansu, and western Inner Mongolia. Compared with the same period in 2019 and 2020, the occurrence of sand and dust storms in the northern China in 2021 had a higher frequency and a larger influence area. The results show that the new generation of FY-4A geostationary satellite has a more complete ability to monitor the interannual variation of dust processes in China.