In order to further reflect the removal effect of coal dust，through  the flue temperture coupling of wet acid ash experimental platform， the dust-containing flue gas dust removal efficiency and particle size of submicron fine particles in simulated flue gas before and after dust removal were tested under the different conditions of cooling，coupling humidification，acidificationan and the changes of the concentration by the acidification evaporation method. The agglomeration and removal performance of submicron fine particles matter were studied. When the temperature of simulated hot dust-containing flue gas is 120 ℃，the absolute humidity is 4.20%，the concentration of ash particles matter is 72.362 μg/m³，during the process of cooling and condensing to the limit of 80 ℃，the humidity，acidity and the particle concentration of fly ash are adjusted to 8.90%，4.183×10^-6，385.27 μg/m³under the optimum working condition，and the mean diameter of the volume distribution of submicron fine particles agglomerates from 20.370 μm to 51.355 μm；After the dust collector，the efficiency of dust collector reaches 99.63%，the submicron fine particles are effectively removed，the mean diameter of the number distribution is reduced from 1.769 μm to 0.869 μm.The experimental result shows that the adsorption of aerosol droplets by fly ash particles is improved， the mutual adhesion between submicron fine particles is enhanced，the agglomeration of submicron fine particles is intensified，and the agglomerate particle size is effectively captured by the dust collector， and the removal and enhancement of submicron fine particles are promoted after flue gas vaporized by temperature coupling humidity acid ash.