In order to select suitable pretreatment methods for cauliflower drying,four different blanching methods were used in this study,which were boiling water blanching,steam blanching,microwave heating and ultrasonic-assisted blanching. Changes in sensory and nutritional indicators of cauliflower were detected after drying,such as shrinkage,rehydration ratio,color,vitamin C,total flavonoids,total phenol and total glucosinolates content. Results showed that the drying time of cauliflower was shortened after different pretreatment methods. Boiling water blanching,steam blanching and microwave heating were shortened by 18.18% compared with untreated samples,and ultrasound-assisted blanching treatment was shortened by 27.27%. After microwave heating and ultrasonic-assisted blanching,the color change of the dried cauliflower products was little. The smallest shrinkage rate was obtained from the ultrasonic-assisted blanching,which was 67.41%. And the rehydration ability of microwave heating was 3.77. Different pretreatment methods had different effects on the nutritional components of cauliflower. Compared with untreated samples,the loss rate of reducing sugar after different blanching methods was 8.85%~23.96%,and the total sugar lost 3.74%~39.35%. The retention rates of soluble protein and total glucoside in dried cauliflower were 81.80% and 31.93%,respectively. After ultrasonic-assisted blanching,the retention rates of vitamin C,total flavonoids and total phenol in dried cauliflower products were 40.18%,83.70%,and 38.40%,respectively. Therefore,the sensory and nutritional quality of cauliflower dried products through ultrasonic-assisted blanching was the best.