The numerical simulation of drying process in ceramic green body was carried out with Fick diffusion model. The influences of hot wind speed, temperature and relative humidity on internal temperature, water content and drying rate of ceramic green body were analyzed within the numerical range of actual drying process parameters. The results show that water loss rate of surface area of green body increases with the increase of hot wind speed, and the wind speed has little effect on water content inside green body. The drying rate inside green body is significantly increases by increasing the temperature, and the maximum drying rate changes by 46.34% when temperature increases from 35 ℃ to 75 ℃. When relative humidity increases from 5% to 85%, the equilibrium water content increases from 0.8% to 5.1% (all are mass fraction), and the increase of relative humidity can improve drying uniformity of green body and ensure the drying quality of green body. The numerical simulation results are consistent with the experimental results. The numerical simulation data provide a theoretical foundation for further research on the heat and mass transfer process in the drying process of ceramic green body and the optimization of the drying curve of ceramic green body.