This study compared the process conditions, physicochemical properties, structural composition, and activity of polysaccharides isolated from leechee peel (LPP) using ultrasound-assisted enzymatic extraction (UAE) and alkali solution extraction (ASE). The results showed that UAE extracted LPP with a total sugar content of 75.65%, significantly higher than that from ASE. The optimal conditions for UAE were extraction temperature of 68.78°C, ultrasonic enzymolysis time of 39.68 min, pectinase dosage of 4.03%, solid-liquid ratio of 1:30 g/mL, and ultrasonic power of 360 W. UAE-LPP was an α-type polysaccharide containing 15.83% uronic acid and showed strong anti-lipid peroxidation and reducing ability. UAE is an effective method to improve the content and activity of natural plant polysaccharides, with advantages of short time, simple process, and easy operation, greatly improving polysaccharide utilization and providing a theoretical basis for LPP development. The study also analyzed the effects of different extraction methods on LPP structure and activity, showing that UAE-LPP had higher total sugar content (75.65%) compared to ASE-LPP (66.23%). UAE-LPP also had higher protein and total phenol content than ASE-LPP. The study demonstrated that UAE is more effective than ASE in extracting LPP, with higher yield and better activity, and has practical application value. The results showed that UAE-pectinase extraction method could extract more LPP, resulting in higher polysaccharide content, which was superior to ASE method, characterized by shorter time, lower temperature, simplicity, and high efficiency. The study also showed that different extraction methods had a certain impact on LPP content, and exploring different extraction methods was of great value to maximize the reuse of leechee by-product resources and avoid resource and energy waste.This study compared the process conditions, physicochemical properties, structural composition, and activity of polysaccharides isolated from leechee peel (LPP) using ultrasound-assisted enzymatic extraction (UAE) and alkali solution extraction (ASE). The results showed that UAE extracted LPP with a total sugar content of 75.65%, significantly higher than that from ASE. The optimal conditions for UAE were extraction temperature of 68.78°C, ultrasonic enzymolysis time of 39.68 min, pectinase dosage of 4.03%, solid-liquid ratio of 1:30 g/mL, and ultrasonic power of 360 W. UAE-LPP was an α-type polysaccharide containing 15.83% uronic acid and showed strong anti-lipid peroxidation and reducing ability. UAE is an effective method to improve the content and activity of natural plant polysaccharides, with advantages of short time, simple process, and easy operation, greatly improving polysaccharide utilization and providing a theoretical basis for LPP development. The study also analyzed the effects of different extraction methods on LPP structure and activity, showing that UAE-LPP had higher total sugar content (75.65%) compared to ASE-LPP (66.23%). UAE-LPP also had higher protein and total phenol content than ASE-LPP. The study demonstrated that UAE is more effective than ASE in extracting LPP, with higher yield and better activity, and has practical application value. The results showed that UAE-pectinase extraction method could extract more LPP, resulting in higher polysaccharide content, which was superior to ASE method, characterized by shorter time, lower temperature, simplicity, and high efficiency. The study also showed that different extraction methods had a certain impact on LPP content, and exploring different extraction methods was of great value to maximize the reuse of leechee by-product resources and avoid resource and energy waste.