The processing of using ultrasonic to cleave saccharomyces cerevisiaeand utilizating cold trchloroacetic acid to extract trehalose was studied. Analysis technique by Ion chromatography was explored. Response surface methodology was employed to research the influence regularity of the five key parameters, such as ratio of water to material R, ultrasonic power W, ultrasonic working time T1, total ultrasonic time T2 and extraction time T3. A dynamic control mathematical model was obtained. The optimum parameters were found as follows: R is 7, W is 698W, T1 is 4.9s, T2 is 7.3min and T3 is 9min. The experimental results indicated that the model is significant, reasonable and effective. The most important factors are as follows: ultrasonic power, ultrasonic working time and total ultrasonic time. It provided certain reference for applying the technology in production.