The invention relates to a gas management process and discloses a purifying and recovering process of absolute dry bag-type converter gas negative energy, comprising the following process steps: gathering gas, lowering the temperature of high-temperature gas, recovering waste heat, lowering the temperature of low-and-medium temperature gas, purifying gas, recovering gas and spreading; by adopting the core processes of waste heat temperature reduction and bag-type filtering, the invention solves the existing defects of large water consumption, high discharging concentration, big energy consumption, low safety factor and high control difficulty by natural cycling temperature reduction and static physical filtration for removing dust, and has the characteristics of water and electricity saving, low discharging concentration, stable and safe discharge, high gas recovering heat value and favourable dust removal effect.