The invention belongs to the field of preparation of 
activated carbon, and particularly relates to a method for preparing 
activated carbon from rice husks. According to the method, 
zinc chloride is used as an activator to treat substances, dissolved in 
zinc chloride, in 
raw material rice husks, saccharides such as glucose and the like are gradually decomposed and then further oxidized into 
uronic acid, 
uronic acid and 
aldose are condensed to form 
furfural, the 
furfural further has a polycyclic 
aromatization reaction to form condensed carbon, finally, an 
activated carbon structure is formed, the activated carbon structure is loose, the porous structure is more stable, and the specific surface area is larger. Alkali 
dissolution is performed with a 
sodium hydroxide solution, 
silicon dioxide in the rice husks is removed, and the 
porosity and activity of carbon are further increased. The more expensive 
zinc chloride can be recycled in the production process, raw materials are easy to obtain, the preparation process is 
pollution-free, and the product is low in 
impurity content, good in looseness, large in specific surface area and high in adsorption capacity.