In this paper, the extraction conditions of polysaccharides from Tenebrio molitor were studied by using the ultrasonic methods with Tenebrio molitor as raw material and distilled water as extractant. The extraction conditions of crude polysaccharides were studied from four aspects: temperature, power, liquid-material ratio and extraction time. On the basis of single factor test, the response surface methodology was used to optimize the crude polysaccharides yield of Tenebrio molitor. Under the condition of ultrasonic extraction, the results showed that the influence of each factor on the yield ranged from the largest to the least: the ratio of liquid to solid, the ultrasonic power, the extraction temperature, the extraction time. The optimal extraction condition of crude polysaccharides yield is the ratio of liquid to solid 25 mL/g, ultrasonic power 300 W, extraction temperature 60 ℃, and extraction time 150 min. Under these conditions, crude polysaccharides yield of Tenebrio molitor is predicted as 2.10%. The measured crude polysaccharides yield reached (2.12±0.04) %, which was well matched with the model predicted yield, indicating that the optimized extraction process of crude polysaccharides from Tenebrio molitor was reasonable. At the same time, the yield of ultrasonically extracted crude polysaccharides from Tenebrio molitor was improved compared with the hydrothermal extraction method under the same conditions.