The utility model discloses an utilize flue gas waste heat based on concentrated system of waste water of liquid column evaporation, the system includes: evaporating column, evaporating column are located one side of desulfurizing tower inlet end and are communicate with the desulfurizing tower, set up spray zone in the evaporating column, spray zone includes the liquid column orifice that is used for spraying waste water of the vertical setting of a plurality of, the flue gas from the flue gas of evaporating column entry get into with the perpendicular or crossing waste water heat and mass transfer who is sprayed by the liquid column orifice of flue gas, waste water absorbs the heat evaporation and produces in the vapor entering flue gas, in evaporating column exhanst gas outlet outflow entering desulfurizing tower, the liquid column orifice is connected with the waste water storage pool, the evaporating column gets into waste water storage pool realization waste water circulation concentration with the waste water that the waste water storage pool is connected after the evaporation, the utility model discloses on the basis of not losing boiler efficiency, utilized the flue gas waste heat, avoided the jam problem, the handling capacity and the moisturizing of desulfurization water of greatly reduced waste water can reach energy -conserving water conservation effect, produce huge economic benefits and environmental benefit.