Abstract: In order to obtain optimization of ultrasonic extraction of polysaccharides from Chuanminshen violaceum, the effect of the solid-liquid ratio, extraction temperature, ultrasonic power, ultrasonic action time and the extraction times of the polysaccharides by single factor experiments and orthogonal experiments in distilled water were investigated. The content of polysaccharides was determined by phenol-vitriol colorimetry method.The decreasing order of importance of the four process conditions affecting polysaccharide extraction was solid-liquid ratio, extraction temperature, ultrasonic power and ultrasonic action time. The orthogonal experimental results showed that the optimal conditions were extraction temperature 70℃, ultrasonic power 140W, solid-liquid ratio 1 ∶40, ultrasonic action time 45min, 2 times. Under this condition, the average rate of extraction of polysaccharides was 47.13%.