Abstract:To improve the extraction efficiency of active components such as salidroside and polyphenols from Rhodiola saccharinensis Boriss，as well as their antioxidant activity，three treatment methods were compared in this study：ultrasound-assisted enzyme-free extraction，ultrasound-assisted single-enzyme extraction （pectinase or cellulase），and ultrasound-assisted composite-enzyme extraction （pectinase+cellulase）. The effects of different enzymatic treatments on the extraction efficiency and antioxidant activity of Rhodiola saccharinensis Boriss were investigated. The salidroside content and polyphenol extraction rate in the extracts were determined by high-performance liquid chromatography （HPLC） and the Folin-Ciocalteu colorimetric method，respectively.Meanwhile，the antioxidant activity of the extracts was evaluated using DPPH and ABTS+ free radical scavenging assays，as well as a total reducing power test. The results showed that the ultrasound-assisted compositeenzyme treatment significantly increased the salidroside content and polyphenol extraction rate，reaching 15.53 mg/g and 13.31%，respectively. The extracts exhibited excellent free radical scavenging activity in the DPPH and ABTS+ assays，with scavenging rates of 87.9% and 99.8%，respectively，and also performed well in the total reducing power test. These findings indicated that ultrasound-assisted composite-enzyme treatment could effectively enhance the extraction efficiency of active components and the antioxidant performance of Rhodiola saccharinensis Boriss，in which the synergistic effect of enzymes played a crucial role.