The invention discloses an energy-saving low-temperature circular heating furnace. The heating furnace comprises a furnace body, a combustor, a high-temperature combustion chamber, a smoke circulating system pipe network, a circulating smoke high-temperature fan, a high-temperature smoke ejector, a control valve, an opened smoke exhausting pipe and a furnace door. The energy-saving low-temperature circular heating furnace has the beneficial effects that the environmental pollution is reduced; the use ratio of heat energy is promoted; the heat convection efficiency in a kiln is increased; the heat treating period of products is shortened; the temperature in the furnace is uniform and the technical quality is optimized; the fuels are fully burnt and the pollution on the products is reduced to the lowest; the heating furnace is strong in adaptability to fuels and can use urban coal gas, generator coal gas, natural gas and liquefied petroleum gas; the construction cost is low and the application scope is wide; the temperature adjustment is sensitive and accurate; and the temperature stability is excellent and the temperature difference in the furnace is small. The energy-saving low-temperature circular heating furnace can be applied to a heat treatment process of magnesium carbon bricks and dehydrating heat treatment processes of unfired bricks and poured prefabricated blocks in the industry of refractory materials.