The flavones in radish seed meal were extracted by hot water method combined with ultrasonic extraction, and the relative ingredients were then desaccharided and deproteinized. The results showed as follows. Under the best condition of liquid ratio 115 (g/mL), with the ultrasonic treatment for 10 min at power 550 W, the radish seed meal medium yellow ketone leaching rate was 1.90%. As for the desaccharidization using alcohol sinking method, the optimal processing parameters are concluded as follows: ethanol concentration was 85%, the flavonoid extract ethanol volume ratio of 13.5, extracted for 4 h. Under this condition, the polysaccharide removal rate was 73.2%, and the loss rate of flavonoids was 34.86%. With the addition of Sevage method for deproteinization, optimal processing parameters are concluded as follows: in the settling time for 20 min, chloroform, n-butanol volume ratio was 31; Flavonoid solution-Sevage volume ratio was 31. Finally, the protein removal rate was 70.06%, and the loss rate of flavonoids was 20.06%.