Aquasorb was prepared with naked oats straw and acrylic acid by graft copolymerization. Adopting orthogonal optimization design to determine the optimal levels of each factor of synthesis conditions, and carried on the various performance was detected. When prepared under the conditions that reaction temperature 70 °C, monomer concentration 12%, the dosage of initiator 1.50%, the amount of cross linking agent 0.15%, neutralization degree 80%, reaction time 3 h, monomer and straw mass ratio 10:1, rotate speed 600 r/min, the water absorbency of the aquasorb was 1012 g/g in deionized water, and 120 g/g in 0.9% NaCl solution. The aquasorb prepared under this condition expressed excellent salt resistance, water holding capacity, acid and alkali resistance.