The invention relates to a high-rehydration and high-safety fruit vegetable or edible fungus non-sulfur drying technique, and is characterized in that the tidied and cleaned fruit vegetable or edible fungus is blanched and scalded, and then is positioned in solvent containing 0.1-0.5 percent of citric acid and 0.02-0.1 percent of cysteine, and through the ultrasonic process which is favorable to protect the color and the drying, the finished product is made. The invention takes comprehensive researches on the blanching and scalding technique, the compositions of the blanching and scalding fluid, the color protecting technique, and the drying technique of the fruit vegetable or edible fungus non-sulfur drying technique; the invention does not adopt the noxious and harmful process methods such as sulphur fumigating, and charcoal-fire firing and drying; the invention can get better color protecting effect by combining organically the advanced ultrasonic process and compound color protecting fluid; and ensures that the finished products can keep fine color, fragrant, taste, and shape after being rehydrated; the invention has high rehydration and high safety. In the case of the bamboo shoot drying, the obtained product is white, the residual value of SO2 is less than or equal to 0.05g/Kg, the rehydration rate reaches more than 5-10, the crispness after rehydration is good, and the invention possesses the characteristic faint scent and the characteristic fresh taste of the fresh bamboo shoot.