Abstract: The WRF-Chem model was used to simulate the vertical transport of atmospheric composition during deep convection over Beijing and its surrounding areas on 21 Jul 2012. The study quantified the contribution of the deep convective system to the redistribution of atmospheric composition with different solubilities. Comparison with Microwave Limb Sounder (MLS) measurements showed that the model simulation accurately reproduced the distribution of CO and O₃ during deep convection. The time and altitude cross-section of CO, O₃, SO₂, and NH₃ demonstrated that deep convection could transport gases with different solubilities to the upper troposphere and even into the lower stratosphere. In the upper troposphere, the volume concentration of low-solubility gas CO increased from 70 ppb (1 ppb=10⁻⁹) to 111 ppb during the convection, representing a 58.6% increase. Conversely, O₃ decreased from 220 ppb to 102 ppb, showing a 53.6% decrease. For high-solubility gases, SO₂ and NH₃ concentrations increased from 0.036 ppb and 0.011 ppb in the preconvection to 0.4 ppb and 0.15 ppb by volume during the convection, with percentage increases of 1011.1% and 1263.6%, respectively.