The invention relates to a flammable gas recycling thermal treatment furnace which comprises a furnace body, a combustion chamber provided with a combustor and an exhaust discharge pipe, wherein a furnace pipe is arranged in the furnace body, a furnace door is arranged at a feeding end, a closed annular hot air channel is formed between the inner wall of the furnace body and the outer wall of the furnace pipe, and a high-temperature glue gas inlet and a flue gas exhaust opening are formed on the furnace body; the combustion chamber comprises a housing which is internally provided with a combustion cavity, wherein an air jet hole and a gas inlet are formed on the housing, the combustion chamber is arranged out of the furnace body, the air jet hole is communicated with the high-temperature flue gas inlet on the furnace body, and the gas inlet of the exhaust gas discharge pipe is communicated with the inner side of the furnace pipe and the gas outlet of the exhaust gas discharge pipe extends into the combustion cavity through the gas inlet on the combustion chamber. According to the furnace provided by the invention, the combustion chamber and the furnace body are independently arranged, the exhaust gas discharge pipe introduces flammable gas generated in the furnace pipe into the combustion chamber to be combusted, and high-temperature flue gas generated by combustion is introduced into a hot air channel to supply energy for thermal treatment, so that energy sources are recycled, the energy consumption is reduced, and the furnace is energy-saving and environmental-friendly, easy to overhaul, simple in integral structure and low in cost.