<p>A large-scale dust event occurs on April 10–14, 2025, in which substantial dust plumes from Gobi and Desert regions are transported by prevailing northwesterly winds to center and south coastal regions, triggering successive heavy dust pollution episodes. Using in-situ observations, reanalysis data, and particle mass flux measurement system, this study investigates the dust source characteristics and vertical–horizontal transport processes. The result shows that the column dust mass flux and near-surface PM₁₀ concentration varied asynchronously along the transport pathway. Only in dust source regions did the two parameters peak simultaneously. In downwind areas, the column dust flux peaked earlier than near-surface PM₁₀, and the lag time increased with transport distance, indicating that upper-layer transport precedes near-surface influence. The evolution of vertical PM₁₀ flux demonstrates that the direction of vertical dust flux shifts with near-surface wind speed: strong winds near the surface entrain coarse particles and produce upward PM₁₀ flux, while weakening winds lead to downward flux and near-surface accumulation. This study reveals the vertical lag structure and flux evolution of long-range dust transport and provides observational support for dust parameterization in boundary-layer models.</p>