Abstract: Extracting technique assisted by ultrasound assisted extraction method of β-carotene from D. Salina was optimized. The result showed that absolute ethanol was the optimal solvent among these kinds of solvent selected, the β-carotene yield of D. Salina was used as measurement index, the sequence of extraction efficiency of different solvent was that absolute ethanol>95% ethanol>absolute ethanol/ acetic ether (2∶1, v/v) >petroleum>chloroform >acetonitrile >acetic ether. The mathematical model of ultrasound assisted D. Salina β-carotene extraction was established by response surface methodology, within the scope of each factor levels, there was no interaction between different factors. The sequence of the effect of three factors on β-carotene yield was that ultrasonic power>ultrasonic time>ratio of liquid to solid. The optimal condition for extraction technique was that L/S 500 m L/g, ultrasonic power 496 W, ultrasonic time 7min, under the optimal condition, the predicted β-carotene yield was 1.282%, and the measured value was 1.273%, it was described that the adaptable of model was good.