With fresh radish as raw materials, the hot-air drying characteristics of fresh radish under different conditions of hot-air temperature, air velocity and slice thickness were investigated in this study. Then the fitting of experimental data and the applicability of 7 different mathematical models for the process of hot-air drying radish was compared. The results showed that the hot-air drying process of radish mainly occured in falling-rate drying period and the constant-rate period is not obvious. Hot-air temperature and slice thickness have a greater effect on drying-rate, relatively, while the effects of air velocity is less. The higher the temperature, the thinner the slice and the bigger the air velocity are, the shorter the drying time is. By comparing the coefficients (R²), chi-square values (χ²) and the root-mean-square error (RMSE) of each model, it was found that, among these models, the Page model is better than other models for describing the process of hot-air drying radish with R² of 0.997 6, χ² of 2.615×10^-4 and RMSE of 0.014 6. It showed a good fitting between the experimental and predicted values. With the increase of hot-air temperature, air velocity and slice thickness, the effective moisture diffusivity of radish increased from 7.560×10^-10 to 2.130×10^-9, and the activation energy was 26.34 kJ/mol. Finally, the color of dried products under different temperatures was examined and analyzed. Results showed that when the hot-air temperature increased from 50 ℃ to 80 ℃, the L^* value showed a gradual decrease, while the values of a^*, b^* and total chromatism ΔE^* were reductive.