The sand and dust weather process affecting Jiangsu Province in the year of 2021 was studied in this paper, and the affected time, regional characteristics and ambient air quality characteristics were analyzed. The results showed that, there were thirteen times of sand and dust weather processes affecting Jiangsu Province, with 229 days accumulated in total. In terms of time distribution, the sand and dust weather processes mostly occurred in January and from March to May, but less occurred in February and November, while no sand and dust weather process occurred from June to October and December. As to the regional distribution, northern Jiangsu was significantly affected by the sand and dust weather processes, cities that had been affected for more than 20 days were distributed in northern Jiangsu. During the sand and dust weather processes, hourly high concentrations of PM₁₀ and PM_2.5 were prone to occur with NNE and NE wind. The ratio of days that the daily concentration of PM₁₀ exceeded the standard affected by the sand and dust weather processes was 38.0%, while the ratio of days that the daily concentrations of PM_2.5 exceeded the standard was only 12.7%. After deducting the influence of sand and dust weather processes, the annual average concentrations of PM_2.5 and PM₁₀ in Jiangsu Province in 2021 lowered by 1 and 6 μg/m³ , respectively. The impact of sand and dust weather process on PM₁₀ concentration was greater than that on PM_2.5. The ratio of days that the ambient air quality with slight pollution or above caused by sand and dust weather processes was 45.0%, and the ambient air quality in northern and central Jiangsu was easy to reach the level of heavy pollution or above, while in southern Jiangsu, it was mostly good or slight pollution, with few moderate pollution. The characteristic of PM₁₀ as the primary pollutant was weakened by the longdistance transmission of dust air mass, the ratio of days when the primary pollutant was PM₁₀ was 83.8%,and the rest were NO₂ or O₃.