The invention discloses a dry-type flue gas desulphurization, denitration and dedusting integrated device and method. The integrated device comprises a flue gas guide device, a reactor, a dedusting device, a draught fan and a funnel which are sequentially connected, as well as a circulation dust fluidization cabin, a humidifying digester, a denitration additive storage bin and a desulphurization absorbent storage bin. The circulation dust fluidization bin is arranged at the bottom of the dedusting device, the output end of the circulation dust fluidization bin is connected with the input end of the humidifying digester, and the output end of the desulphurization absorbent storage bin is also connected with the input end of the humidifying digester. The output end of the denitration additive storage bin is connected with at least one of the input end of the humidifying digester and the flue gas guide device. The invention has the advantages of simple process, small occupation, low one-time investment and low operating cost, the SO2 removing efficiency is 80 to 95%, the NOx removing efficiency is 40 to 65%, and the dust emission concentration is less than 50 mg/Nm<3>. The desulphurization and denitration efficiency of the invention can meet the requirement of environmental protection, the running resistance of the device is low, and no sewage generates during the desulphurization and denitration processes. The final product is dry powder and can not cause any secondary pollution, the flue gas can be directly discharged without the need of heat exchange, and the added denitration additive has the synergistic effect with the absorbent to strengthen the removing of the SO2, thereby enhancing the desulphurization efficiency.