Abstract: Using the automatic monitoring data of ambient air, laser radar observation data, and meteorological data in Zhejiang Province from 2014 to 2023, a backward trajectory model was used to analyze and study the changes of dust weather in Zhejiang Province. It explored the transmission and source characteristics of typical dust processes. The results showed that there were 25 sandstorm weather processes in Zhejiang Province in the past 10 years, lasting 265 days, mainly occurring in cities around Hangzhou Bay. The frequency and intensity of sandstorm weather processes showed an upward trend. The proportion of spring sandstorms was 75.8%, with 37.0% occurring in April, the highest of the year. The main reason for the typical sand and dust process on April 11, 2023 was that the sand and dust air mass was affected by cold air and pushed southward to the area around Hangzhou Bay, and then pushed southward towards the Jinqu Basin due to the backflow of sand and dust from the sea. On the day of April 12 and the afternoon of April 13, the sand and dust flowed back to the eastern coast of Zhejiang and the area around Hangzhou Bay, and the rainfall belt moved eastward, causing the area around Hangzhou Bay to continue to be affected by floating dust. The chemical composition of PM_2.5 in various cities was dominated by crustal elements such as silicon, iron, and calcium, and the concentration of crustal elements increased from north to south. The clustering trajectory of air masses was mainly short distance, but the concentration of pollutants was higher under the influence of long distance.