A desulfurizer compounded by industrial wastes and a production method thereof separately relate to a desulfurizer and a production method thereof. The desulfurizer uses carbide slag, iron-making slag and coal ash slag as basic materials and is an efficient compound desulfurizer used in the dry desulphurization of the circulating fluidized bed boiler, wherein the mixing percentages of carbide slag, coal ash slag and steel slag powder are 30-40%, 50-60% and 10-5% respectively. The production method comprises the following steps: crushing and grinding carbide slag and steel slag to powder of being less than 100 microns, screening coal ash slag to obtain particles of 1-2 mm, performing hydration treatment according to the percentages, placing in a stirrer to fully stir, drying, and screeningto obtain the product, wherein the particle size of the qualified product is 1-2mm through inspection. When the ratio of Ca/S is 2.5, the desulphurizing rate of the desulfurizer of the invention is more than 80%; the processing equipment is simple, the investment cost and operating cost are low; and the existing consumption technology and equipment are not changed and the boiler efficiency and the electricity consumption of the fan are not obviously affected. The desulfurizer of the invention can be popularized in the desulfurization of the circulating fluidized bed boiler.