Calcium hydroxide (Ca(OH)2) with outstanding sulfur dioxide (SO2) adsorption properties was synthesized through the utilization of calcium oxide (CaO) with a urea solution via a digestion method. This innovative calcium-based desulfurizer aims to meet the needs of low-temperature dry flue gas desulfurization in the steel industry. Fixed-bed experiments were conducted to investigate the impact of different water-ash ratios, urea solution concentrations, and digestion time on the desulfurization efficiency and particle structure of the desulfurizers. Sample CAC-2–0.1 U exhibited outstanding desulfurization performance, achieving 100 % removal efficiency, a sulfur capacity of 34.64 mg/g, and a breakthrough time of 142.6 minutes under target flue gas conditions. The sample also displayed a high specific surface area of 22.10 m2/g and demonstrated adaptability under varying operating conditions. Characterization and reaction mechanisms of the desulfurizer were studied using XRD, SEM, BET, XPS, ICP-OES, and Materials Studio software. Experimental data was analyzed through pseudo-first-order and pseudo-second-order kinetic equations, and intra-particle diffusion model. The product's strong adsorption capacity for SO2 positions it as a highly promising adsorbent for controlling low-temperature flue gas emissions in the steel industry.