The invention relates to a method for simultaneously reducing dust and recycling arsenic from a nonferrous smelting flue gas. The method comprises the following steps: introducing a smelting flue gasinto a dust collection zone of a dust-collection arsenic-removal integral device, and baffling flue gas dust by using a baffle tube to implement adsorption dust collection; feeding the flue gas afterdust collection into an arsenic separation zone, and cooling low-grade solid arsenic; heating the low-grade solid arsenic in an arsenic removal zone, converting the low-grade solid arsenic into high-grade gaseous arsenic, performing quenching, and performing arsenic collection, so as to obtain high-grade solid arsenic. By adopting the method, functions of dust collection and arsenic separation areachieved simultaneously by using one device, so that flue gas treatment procedures are reduced, and the flue gas purification efficiency can be improved.