Optimal energy-saving method for controlling surface pollutant discharge of steam boiler

The invention discloses an optimal energy-saving method for controlling the surface pollutant discharge of a steam boiler. The method comprises the steps of firstly controlling the flow of pollutant discharge according to the steam flow proportionally, and continuously diluting water in the steam boiler as required; on this basis, configuring a conductivity close loop control circuit to prevent the influences, such as water supply salinity fluctuation, flow rate measurement error, boiler bottom periodic pollutant discharge and the like, and coupling the both by an addition logic unit so as to form a feedforward-feedback complex control system. The invention can prevent various interferences, stably keep the salinity of the water in the steam boiler above the desired level, and realize the optimal energy-saving and emission-reducing effects by the least pollutant discharge amount.