The invention relates to a low-temperature hot air circulation heat treatment furnace applicable to a non-crystalline or ultra-crystalline
magnetic core or a magnetic ring, and an application method of the heat treatment furnace. The heat treatment furnace comprises a furnace body, wherein a
heating furnace pipe, a first heat treatment furnace
pipe and a second heat treatment furnace
pipe are arranged in the furnace body; the first heat treatment furnace pipe is provided with a control valve I and a control valve II; the second heat treatment furnace pipe is provided with a control valve III and a control valve IV; the
heating furnace pipe is internally provided with a heating device and a
centrifugal fan; the furnace body is externally provided with a
gas pipeline connected with a vacuumizer; and the
gas pipeline is communicated with the two furnace pipes, provided with a ventilation valve I and a ventilation valve II, and connected with a gas inlet pipeline communicated with
inert shielding gas. The heat treatment furnace and the application method have the benefits that 1) the two heat treatment furnace pipes are alternately used, so that
waste heat is utilized effectively, and the
energy consumption is reduced; 2) a
convective heat transfer mode is adopted, so that temperature uniformity and the transfer speed are ensured, and the product quality is improved; and 3) the furnace loading quantity of a product is increased; a heat treatment space of the product is utilized effectively; and the
energy consumption of the single
magnetic core is reduced.