The invention provides an underflow-like
constructed wetland type water treating method. According to the water treating method, water flows into a reaction cavity through water distribution holes,
carbon source portions release organic matters into the water after being immerged into the water,
oxygen content of the water in a lower cavity body is not larger than 2mg / L, the ratio of the total concentration of the organic matters in the water in the lower cavity body to the total concentration of Kjeldahl
nitrogen in the water outside the reaction cavity is larger than 4, and accordingly, in the lower cavity body, anaerobic
microorganism films are formed on biological stuffing units outside the
carbon source portions, and the water is subjected to
denitrification reaction on the
anaerobic microorganisms; the water after being denitrified flows into an upper cavity body through flow guiding holes in flow guiding pieces; gas releasing portions in the upper cavity body release dissolved
oxygen into the water, the
oxygen content of the water in the upper cavity body is not smaller than 6mg / L, and accordingly, aerobic
microorganism films are formed on the biological stuffing units outside the gas releasing portions, and the water on the aerobic
microorganism films is subjected to
aerobic reaction. The underflow-like
constructed wetland type water treating method used for water purification is convenient to operate and high in water purification efficiency.