The invention discloses a preparation method and an application technology of a dimethyl diallyl ammonium chloride modified towel gourd vegetable sponge adsorbent, and is characterized in that the preparation method comprises the steps: peeling and denucleating mature fruits of towel gourd, washing with water to remove soil and impurities, drying, crushing, and carrying out chemical treatment drying to obtain acylating-chlorination towel gourd vegetable sponge; adding, by the mass percentage, 56-71% of dimethyl diallyl ammonium chloride, 10-20% of the acylating-chlorination towel gourd vegetable sponge, 12-26% of water and 0.5-2.0% of ammonium persulfate into a reactor, wherein the sum of the percentages of all the components is 100%; under the nitrogen protection and at a constant temperature of 45-55 DEG C, stirring and carrying out a reflux reaction for 4-5 h; and after cooling, washing with deionized water, carrying out suction filtration until a filtrate is neutral, drying in a vacuum drying oven, and thus obtaining the dimethyl diallyl ammonium chloride modified towel gourd vegetable sponge adsorbent. The adsorbent has the advantages of quite high adsorption capacity on grease, excellent physicochemical and mechanical properties, strong regeneration capacity, capacity of being repeatedly used many times, low cost, greenness and environmental protection.