Abstract: Study acidity regulator, ethanol concentration, pH, solid-liquid ratio, time, temperature, ultrasonic power and frequency on the effect of ultrasonic field red cabbage pigment extraction, determine citric acid as acidity regulator, pH2 10% ethanol solution as extracting agent, ultrasonic (40kHz, 0.25W·cm-2) was unultrasonic leaching rate increased by 55.88%. The optimized levels of ultrasonic conditions were determined by the uniform experiment with mixture. The result showed that the optimized levels of three factors were respectively 1 ∶60g/mL, 135kHz, 0.45W·cm-2, 60℃, 15min, extraction rate 53.37%. The isothiocyanates content in extracting solution of pH2 by non-ultrasonic was 0.17%, which was in 10% ethanol ultrasonic extracting (28kHz, 0.25W·cm2) solution up to 0.47%, and with the increase of ultrasonic frequency isothiocyanates in the extractingsolution content reduced.