Using single factor method and orthogonal experiment,the study takes Kaolin and corn straw as raw materials and H3PO4 as activator and dips them in different activator concentration,different kaolin and corn straw mass ratio as well as different impregnation ratio under different conditions, and then carbonize them in low temperature by electric furnace, muff calcining to prepare kaolin/corn straw composite adsorption material.The adsorption capacity for methylene blue solution was characterized by T6 visible spectrophotometer,and automatic specific surface area and porosity analyzer was used to characterize the composite adsorption material under the optimal experimental conditions. The results show that the optimal experimental conditions are: Under the conditions of 25% Concentration of H3PO4 , 1:4 mass ratio of kaolin to corn stalk and 2.5:1 impregnation ratio, the adsorption value of methylene blue on the composite adsorbent is 1.116mg/g, the specific surface area is 7.56m2·g-1 and the single specific surface area is 6.82m2·g-1. The microporous volume was 1.24×10-8mL·g-1 and the microporous area was 0.57m2·g-1,the results show that the pore structure of the composite adsorbent is not uniform, and there are a lot of micropores and a certain amount of mesopores in the samples.