Abstract: To improve the utilization of cassava by- product, the leaves of four edible cassava varieties, including‘SC9’,‘SC12’,‘SC6068’and‘Reyin No.1’were used as materials, the effects of different cyanide removal treatments on cyanide, total flavonoids and proteins of tender leaves, young leaves, and mature leaves were compared and analyzed, and then the principal components analysis were conducted by SAS system. The results showed that the nutrient loss of dried leaves was less, but the cyanide content was significantly higher than the food safety standard, while the cyanide content of leaves after 70℃ water bathing treatment was within the scope of the food safety standard, but the total flavonoids reduced sharply. In terms of varieties and various indicators of leaf growth stages, there were significant differences among varieties, and there were also significant differences at different growth stages. The total flavonoids of‘SC6068’were the highest, reaching 31.663 mg/g. According to the comprehensive evaluation of principal components, from the point of the growth stages, leaves of four varieties of drying treatment was better than the 70℃ water bathing treatment, but cyanide content was high. From the point of varieties, the drying treatment of two varieties‘SC12’and ‘SC6068’was better than the 70℃ water bathing, and the comprehensive evaluation value of F1 was 2.5892, 2.5272 respectively, which would be considered as a way of resource utilization for food to develop antioxidant active substances. In conclusion, this study shows that the processing and utilization methods of different cassava varieties are closely related to the total flavonoids and cyanide of leaves, and direct drying has less influence on total flavonoids, which is suitable for processing fermented feed, while the cyanide is decreased after 70℃ water bathing treatment, which is suitable for food processing.