The invention discloses a preparation method of a natural reed stalk adsorption material. The preparation method comprises the following steps: selecting natural reed stalks, cleaning, pounding, drying, grinding, sieving, and then sequentially performing HNO3 and NaOH refluxing, water washing and drying to obtain reed stalk cellulose; and then performing reaction crosslinking on an NaOH solution and epoxy chloropropane, mixing crosslinked cellulose with 3-chlorine-2-hydroxypropyl sodium sulfonate, a dioxane aqueous solution and an Na2CO3 solution, reacting by controlling the temperature to be 50-60 DEG C, finally sequentially performing cross washing on a product by using acetone and water, and performing vacuum drying after completely cleaning the product to obtain a reed stalk adsorption material finished product. A preparation process disclosed by the invention is short in time consuming and cheap in raw material, is pollution-free, and has wide application prospects.