Using the MICAPS, NCEP, and the monitoring data of atmospheric composition from environmental monitoring stations, the floatingdust and heavy air pollution process on 29 March 2015 in the Lianyungang area is analyzed. The results show that after the dust weather in the upstream area, a large number of dust particles carried by the northwest air affected the local area， resulted in the floating dust. There were westerlies at the upper levels and increasing sinking motion at 400 hPa, and the high altitude momentum transmission is the dynamic condition for the floating dust. In a weak pressure field, the atmospheric stability and wind are weak, and the air is dry, which are conducive to the spread of dust particles and pollutants. The backward trajectory simulation of dust particles indicates that the sand source is from the eastern region of Mongolia, consistent with the high altitude situation analysis.