Abstract: Based on the theoretical analysis and test research, it is found that the aim of So_x and No_x removal from the flue gas could be attained using the boiler's alkaline discharge water or chemical alkaline water to spray on the boiler's toe flue, and the better effect is obtained. The key techniques are the spray mode,amount and alkalinity of water,as well as the influence of flue structure on the mixed turbulency between gas-vapor two phase flow. This method has the characteristics such as lesser investment, lower operating cost, simple and reliable operation, better effect of sulfur and nitrogen removal, without secondary pollution and lesser resistance influence and corrosion on flue. This method has the wide application prospects with respect to the characteristics of coal combustion boilers in our country.