In order to improve the quality of lily production and shorten the drying period, taken Lanzhou lily as sample and used JK-LB1700 thin layer drying test bed to dry. The effects were investigoted, in different hot-air temperature (60, 70, 80, 90 ℃), hot-air rate (0.5, 1.0, 1.5, 2.0 m/s) and drying relative humidity (20%, 30%, 40%) on drying rate, color ΔE* value, vitamin C content, rehydration ratio during lily drying and law of change. The Weibull distribution function was used to simulate the drying moisture diffusion law of lily. Results, the drying time of lily was significantly shortened (P＜0.01) with the hot air temperature and hot air speed increasing. There was no difference under different drying relative humidity, but the humidity was positively correlated with the drying rate of the lily in the early drying stage, and negatively correlated in the later stage.Weibull distribution function can accurately (R²＞0.99) describe drying process, and basing on Weibull distribution function, effective water diffusion coefficient was obtained between 1.213×10 ^-6~3.992×10^-6 m²/s. Deff values were not only affected by drying parameters, but also by drying equipment and sample storage time. The combined effects order of experimental drying parameters on the color ΔE* value, vitamin C content and rehydration ratio were dry temperature＞hot air speed＞relative humidity, and the quality index color ΔE* value and vitamin C content were greatly affected by drying parameters, rehydration was relatively small.