In order to understand the influence mechanism of dust events on PM10 pollution, the characteristics of atmospheric boundary-layer structure and turbulent flux transport during different kinds of dust events in Lanzhou and their relation with PM10 pollution were analyzed by using the data of PM10 concentration, gradient measurements of meteorological tower and turbulent flux measurements observed at SACOL. As dust events break out, the strong inversion in the boundary layer breaks and a mixing layer develops quickly. With the rise of wind speed, PM10 concentration increases sharply. If there is obvious dust transport from upstream regions, the peak of PM10 concentration can lag behind the peak of wind speed. The vertical transport of momentum flux is very strong. The turbulent momentum downward transport, especially the downward momentum flux of meridional velocity, is the main factor which causes the dust blowing and the heavy PM10 pollution during dust events.