The drying characteristics of burdock were studied using self-made weight and temperature facilities. The moisture content and the internal temperature were acquired online. Taken microwave power density, temperature and sample depth as the influence factor, and the optimal parameters for drying burdock by microwave were obtained through orthogonal experiment. The optimized parameters were as followed: the power density 10 W/g, the internal temperature of sample 60 ℃, and the samples thickness 2 mm. Under these conditions, the rehydration rate R value and the color difference ΔE value of dried burdock were 3.77 and 64.37, respectively. ANOVA of the evaluation index showed that the drying time was extreme significant affectedly by the power density and samples thickness, and significantly affected by the internal temperature of sample.