The invention discloses a waste-gas-heat recovering device of a setting machine. The waste-gas-heat recovering device comprises more than one group of waste-gas-heat recovering equipment, wherein each piece of waste-gas-heat recovering equipment comprises an inner pipe, wherein a gas inlet of the inner pipe is communicated with the inner part of the setting machine; an outer pipe is sheathed outside the inner pipe; a gas outlet of the outer pipe is formed in the setting machine; radiating fins are arranged between the outer wall of the inner pipe and the inner wall of the outer pipe. The waste-gas-heat recovering device disclosed by the invention has the advantages that the temperature of waste gas exhausted by the setting machine can be reduced quickly, air is heated by the waste gas and then is supplied into the setting machine, so that the energy-saving purpose is fully achieved and energy is saved by 25-30% compared with that in a setting machine without improvement; the improved setting machine has no bad influence on original production equipment and can guarantee the normal conduction of production; the waste-gas-heat recovering device does not need to be disassembled and cleaned.