The invention discloses a wet method smoke gas denitration technology of two segments of liquid phase oxidation and absorption, which adopts solution or mixtures of one or more of potassium permanganate, sodium chlorite, sodium hypochlorite, calcium hypochlorite, oxyful and chlorine dioxide as oxidizing agents to ensure nitrogen oxide in smoke gas contact and react with the oxidizing agents. After the nitrogen oxide is partially oxidized into nitrogen dioxide, oxidized nitrogen oxide in the smoke gas is absorbed by alkali liquid to generate corresponding nitrite. The technology adopts liquid phase oxidation to replace gas phase oxidation so as to reduce the investment and the running cost, simplify the technical process and the system structure, and enhance the operability. Compared with a method that oxidation and absorption are simultaneously carried out in the liquid phase, the two-segment technology not only can increase the removal efficiency, avoid secondary pollution caused by incomplete absorption of NO2, but also can achieve the purposes of selectively generating and recovering the nitrite in the absorption stage by controlling the oxidation degree of the oxidation stage.