The invention provides a bag type dust removing technology for blast furnace gas, which has the process flow as follows: (A) waste blast furnace gas which flows out from a blast furnace is processed through rough dusting by a gravity dust collector and then become half-cleaned gas; (B) the half-cleaned gas obtained from the (B) passes through a temperature buffer device, the temperature disturbance of the half-cleaned gas is buffered, and then the half-cleaned gas enters into a bag filter; (C) after being processed through refined dust removing by the bag filter, the half-cleaned gas becomes clean gas, which becomes low-pressure and low-temperature clean gas provided with chloride ions through the power generation by a TRT device or a reducing valve set, and then the clean gas provided with the chloride ions enters into a chlorine removing device; dust collected by the bag filter is transferred to a large dust storehouse by a dense-phase dust conveying device; (D) the dust becomes clean gas after being dechlorinated by the chlorine removing device, and enters into a gas pipe network for being used by a user. The temperature disturbance of the gas which enters into a bag is buffered, thereby preventing the bag from burnout or preventing the bag from scorching caused by the caking; by adopting the dense-phase dust conveying manner, the bag type dust removing technology has the characteristics that the conveying capacity is big, the energy consumption is low, etc.