Response surface analysis was proposed to optimize the ultrasound-assisted extraction process of crude polysaccharides from bulbils. The effects of solid-liquid ratio, ultrasonic power and extraction time on crude polysaccharide yield were investigated by single factor experiments. Response surface analysis was carried out by using the crude polysaccharide yield as response value and the box Behnken method to design the experiments. The optimum extraction conditions were obtained as follows: solid-liquid ratio, 18∶1 (mL/g), ultrasonic power, 760 W; extraction time, 23 min and the crude polysaccharides yield could be up to 60.68%, which agreed with the predicted value (the relative error is 2.03%). The results demonstrated that it is reasonable and practicable to optimize the ultrasonic extraction process using response surface methodology.