The complete flue gas purification device of the carbonization furnace consists of two tanks, one is spray and the other is condensation. The smoke generated in the furnace is first introduced into the spray tank through the first process, transforming the burning hot gas into water vapor. After purification into water vapor, it enters the condenser, where the water vapor is treated and turned into water droplets, cooled into water droplets, and there is no smoke when it comes out.