TThe invention discloses a dust removal and desulphurization device of a roasting kiln, which comprises a flue gas dust removal tower, a desulphurization tower, a circulating neutralizing tank, an overflow pipe, a slag discharge pipe, an air blower, a high-pressure circulating pump and an annular dust hood, wherein the upper part of the desulphurization tower is provided with a fresh air discharge outlet, and the lower part of the desulphurization tower is provided with an impact bathing tank; the inner upper part of the flue gas dust removal tower is provided with a central spray header, and the inside of the tower is provided with a plurality of obconical liquid collecting boards; the flue gas dust removal tower is sheathed into the desulphurization tower; the upper and lower parts of a space between the inner wall of the desulphurization tower and the outer wall of the flue gas dust removal tower are respectively provided with a gas-liquid separator and a packing layer, and peripheral spray headers are arranged below the gas-liquid separator and the packing layer; the impact bathing tank is provided with the slag discharge pipe and the overflow pipe, the slag discharge pipe is connected with the circulating neutralizing tank, and the overflow pipe is connected with the slag discharge pipe; the air blower is connected with the fresh air discharge outlet, the water inlet of the high-pressure circulating pump is connected with the circulating neutralizing tank, and the water outlet of the high-pressure circulating pump is respectively connected with the central spray header and the peripheral spray headers by water pipes; and the annular dust hood is arranged at the top of the roasting kiln, and is connected to the top of the flue gas dust removal tower through a flue gas inlet pipe.