The invention relates to a processing method of primary-color efficient smallanthus sonchifolius dry powder. The processing method comprises the following steps of (1) performing high-oxygen pretreatment through cooperation of ultrasonic waves and a magnetic field; (2) performing cleaning and sterilization; (3) performing cutting into slices through water jetting; (4) performing co-activating andsprinkling; (5) performing passivating and mist spraying; (6) performing microwave-freeze drying; (7) performing caking-resistant mist spraying; and (8) performing high-speed nitrogen gas current crushing: performing crushing with N2 current of which the concentration is greater than or equal to 99.999%, performing separation from oxygen, performing direct bagging and packaging at a discharge opening to obtain smallanthus sonchifolius whole powder, wherein the average particle size of products is 2-200[mu]m. According to the method, the primary-color efficient smallanthus sonchifolius whole powder can be in multiple united production, 4 great individual brown stains due to polyphenol substrates, polyphenol oxidase, an enzymatic brown stain system and a quinone non-enzymatic polymerizationof the smallanthus sonchifolius can be avoided, a brown stain phenomenon at the moment of conventional cutting and film preparation caused by differences of sugar, acid and metal trace elements can beavoided, the color value of the product is increased by 21%, and the production efficiency is improved by 30%-40%.