In order to compare the effects of different longwave radiation and shortwave radiation parameterization schemes on the numerical simulations of radiation fog processes, in this paper, the two typical heavy radiation fog events occurred in Jiangsu Province in spring and autumn 2015 are screened respectively and the Weather Research and Forecast Model (WRF) is used in the numerical simulations of these two radiation fog processes through the design of different longwave and shortwave radiation parameterization schemes. The influences of these longwave and shortwave radiation parameterization schemes on the numerical simulation of the fog processes are discussed. The mean absolute error (MAR), the root mean square error (RMSE), the Pearson correlation coefficient and Fog Grade and the Fog Area Forecast Regulations promulgated by the China Meteorological Administration are used to evaluate these simulation schemes, and the optimal simulation schemes under the different conditions are obtained. The results show: (1) In the simulations of the relative humidity and the dew point temperature as the vapor conditions of fog occurrence or in the simulations of the air temperature and surface temperature as the thermodynamic conditions, the optimal scheme is the combination of GFDL scheme in the long wave radiation with the RRTMG scheme in the short wave radiation. (2) In the simulations of the wind speed at the 10 m level, for the dynamic condition of fog engendering, the optimal scheme is the combination of CAM scheme in the long wave radiation with the FLG scheme in short wave radiation. (3) For the simulation of the fog area, the scheme combined with the best simulation effectiveness is the combination of the GFDL scheme in the long wave radiation with the RRTMG scheme in short wave radiation.