Abstract: Taking fresh purple potato as raw material, study the technology parameters of hot - air drying purple sweet potato. Through the single - factor test, studied the influences of the paving material density, the hot air temperature and the wind speed on the hot - air drying characteristics of the purple potato, and obtained the dehydration law of the purple potato in hot - air drying process. Meanwhile, analyzed the influences of the main process parameters (air temperature, paving material density, wind speed) on drying time, energy consumption, chromatic aberration and content of important nutrients of the purple sweet potato in the hot - air drying process. The results showed that the hot air temperature and the paving material density had a great impact on the drying rate, and the hot air wind speed had a certain influence on the drying rate. The optimization of process parameters are as following:hot air temperature was 90℃, the paving material density was 0. 1592g/cm², hot - air wind speed was 0. 6m/s, and in this condition, the composite indicator was 19. 5678.