The utility model relates to an airflow bed reacting furnace. The airflow bed reacting furnace comprises a furnace shell, a furnace end fixed at the upper part of the furnace shell, a material outlet arranged at the bottom of the furnace shell, a gas flue arranged on the side wall of the furnace shell, and a combustor fixed above the furnace end, wherein the combustor comprises a combustion-supporting air pipe, a material conveying annular pipe and a fuel conveying annular pipe which are embedded and sleeved from inside to outside in sequence. According to the airflow bed reacting furnace, the technological process of aluminum oxide roasting activation in fly ash is shortened, the technological process is more simplified, the volume of exhaust gas in the airflow bed reacting furnace is reduced by more than ten times compared with the conventional normal pressure reacting furnace, the volume of required combustion chamber is reduced by about ten times, and the manufacturing cost of the reacting furnace is reduced by four to five times.