One accumulative heating steel / iron furnace combustion method and its device applied in metallurgical field without draft fan and selector valve. Accumulative heating and baking technology is one of the important development directions of baking and heating technology. In traditional equipment, the components such as induced fan and directional valve are damaged easily and maintained frequently. The non-induced fan and non-selector valve accumulative heating steel / iron furnace combustion method is realized by aiding combustion air, preheating of gas when transportation and heat recovery of exhaust gas. The device includes a burner, a aiding combustion air transmission system, a gas transmission system and an exhaust gas emission system. By implementing the technical scheme proposed by the invention, the enterprise can save a large amount of maintenance expenses and reduce energy consumption. While achieving the effect of energy saving and emission reduction, the maintenance personnel can easily replace the fault device and shorten the maintenance and repair time, and then shortens the production cycle and provides a guarantee for increased production.