In order to further study the vertical distribution characteristics of meteorological elements and pollutant concentrations in the boundary layer of radiation fog events, a comprehensive observation test of boundary layer and pollutants was carried out in Donghai County by UAV in the winter of 2020. It is found that the thickness of inversion layer in foggy days is tens to hundreds of meters thicker than that in sunny days, and the strength is stronger by 0.5-1℃/hm. On foggy days, there is wind shear at low altitude, and the wind direction changes little in the vertical direction. On sunny day, the wind speed changes little at low altitude, and the wind direction rotates clockwise with height at low altitude. The intensity of radiation fog with deep single-layer inversion structure is stronger than that of double-layer inversion structure. In the same radiation fog process, the intensity of fog will not change with the change of wind direction, and the lower wind speed is more conducive to the formation of strong fog. From the perspective of vertical distribution of pollutants, TVOC at the same height in the inversion layer is higher in sunny days than in foggy days. Before and during the generation stage of radiation fog, the decrease rate of SO₂ concentration with height is much higher than that in the same period of sunny days. In sunny and foggy days, the vertical changes of O₃ and NO₂ show obvious negative correlation, and NO₂ shows a negative gradient change. PM_1.0, PM_2.5 and PM₁₀ are more than twice higher in foggy days than in sunny days. CO is relatively stable in the process of radiation fog with little vertical change. TVOC, NO₂, PM_1.0, PM_2.5 and PM₁₀ will be affected by the strong inversion in the process of radiation fog and accumulate in the inversion layer. The cumulative change rate of particulate matter is more significant than that of gas, and the cumulative change rate of particles with large particle size decreases more than that of particles with small particle size. The decrease of PM_2.5 concentration will reduce aerosol optical thickness and promote photochemical activity photolysis reaction, resulting in a negative correlation between PM_2.5 and O₃ vertical change. After sunrise, the solar radiation is enhanced, and the development of unstable boundary layer is accompanied by the downward mixing of O₃ in the upper air, which leads to the increase of O₃ and the increase of PM_2.5 emission, making the vertical changes of the two more consistent.