It is an feasible way to realize the zero liquid discharge(ZLD) by using the waste heat from the flue gas of the coal-fired power plant to evaporate the spray of the FGD wastewater. In this paper, the evaporation and flow characteristics of atomized droplets in a high temperature flue of a 330 MW coal-fired power plant were studied by numerical simulation, and the droplet impinging condition at different atomizing mouth angles and the evaporation of droplets under different loads were investigated. The results show that in 50%,75% and 100% boiler load, the higher the temperature and the faster the speed of the flue gas, the less the time it takes for the complete evaporation of the droplets, and the maximum life time of droplet is between 2.85~3.36s. When the optimum atomization cone angle of a single flue structure is 65°, the size of vortex is inversely proportional to the distance between sprayer and the flue wall, which is conducive to the continuous diffusion of the local droplets from the nozzle region to other regions.