Polysaccharides derived from pumpkin have garnered increasing interest due to their diverse biological activities. In this study, pumpkin polysaccharides were extracted using an ultrasound-assisted extraction method, optimized via response surface methodology. The optimal extraction conditions were identified as follows: a solid-liquid ratio of 1:60 (g/mL), an extraction time of 1.9 h, an extraction temperature of 62 °C, and an ultrasonic power of 286 W. Under these conditions, the total carbohydrate content in pumpkin polysaccharides reached 71.14 ± 1.53 %, closely aligning with the predicted value. Post extraction, the polysaccharides were purified using DEAE Sepharose Fast Flow and Sephadex G-100 columns, resulting in a pure fraction termed PPS3. Structural analysis revealed that PPS3, with a molecular mass of 5.96 × 10