The ultrasonic wave withdraws the purple sea cabbage natural pigment and the nature auxiliary studies the abstract: Take the edible purple cabbage as raw material, does with the distilled water soaks raises the medicinal preparation, uses method study purple sea cabbage pigment extraction process which the ultrasonic wave auxiliary water immersion raises, and to its thermostability, to light stability and metal ion pair pigment influence and so on. The experimental result indicated that withdraws the purple sea cabbage pigment the best technological conditions is: As soaks take the distilled water raises the medicinal preparation, liquid solid compared to is 40:1(mL:g), pH is 7, the supersonic auxiliary power 80%, soak raises time 50min, under this condition the cyanine extraction rate reaches , and reduced greatly compared to the traditional process has soaked proposes the time. Indicated to its nature's analysis: The purple sea cabbage pigment is good to the light stability; Is also very stable under the room temperature, the temperature increment its degeneration speed speeds up; K+, Na+, Cu2+, Mg2+, Zn2+, the Ga2+ plasma does not have the influence basically to the pigment, Fe3+, Al3+, Sn2+ and so on has certain influence to its stability. key word: Sea cabbage pigment; Natural pigment; Supersonic; Extraction