［Objective］ This study aimed to explore the appropriate pretreatment method of lotus root heat pump after drying.［Methods］ Color protection (CP),osmotic dehydration (OD),ultrasonic color protection (USCP ),ultrasonic osmotic dehydration (USOD ),color protection + ultrasonic osmotic dehydration (CP+USOD ) and ultrasonic osmotic dehydration synchronous color protection (USOD -CP) pretreatments were applied to the pretreatment of lotus root heat pump before drying.Their effects on the appearance color,microstructure,nutrient composition and antioxidant activity of dried lotus root were explored.［Results］］ Applying ultrasound during CP and OD can enlarge the microscopic pores of lotus roots.With levels of 15.64 and 21.08 mg/ 100 g,respectively,lotus root polyphenols and niacin processed by USCP were the greatest,while the color difference value was the lowest at 5.02.The contents of flavonoids and total free amino acids in lotus root in the USOD -CP group were the highest,which were 207.05 and 149.04 mg/ 100 g,respectively.The scavenging rates of USCP and USOD -CP pretreated lotus root were 45.96% and 45.94%,respectively.Polyphenols have the strongest correlation with hydroxyl radical scavenging.［Conclusion］ USCP and USOD -CP pretreatment before the lotus root heat pump drying can further improve the drying quality of the lotus root.