This paper briefly introduces the managing technology of sintering flue gas, and a new method of material balance for activated carbon is put forward. According to the problem of flue gas treatment at present, this method firstly calculates the discharge speed of the roller feeder in front, middle and back at the bottom of absorption towers, and establishes the mathematic relationship between running speed and the discharge quantity of the roller feeders, which the former could be converted into the latter. Then it calculates and gets the roll feeder speed of the analytical tower according to discharged quantities from all the feeders of adsorption towers. The deviation from the process control would be regulated by closed loop control. By this way, the material balance control among the analytical tower, the conveyors and the adsorption towers could be well realized. Finally, the material balance about single adsorption tower or analytical tower is introduced.