Sulfur dioxide is one of the major pollutants resulting from fuel combustion. In this study, CaO and attapulgite were utilized as raw material for synthesizing CaO/attapulgite(CaO/ATP) desulfurizer. The performance of samples was studied in dynamic conditions. Major factors affecting the desulfurization such as weight ratio of CaO to total, types of modifiers, desulfurizer particle size, bed temperature were investigated. The desulfurization agent synthesized under optimal synthesis conditions with an CaO content of 30 wt% and an NaOH modifier, and the desulfurization reaction processed under optimal synthesis conditions with water content of 20~30wt%, a particle size of 1/10 of desulfurization tower diameter and room temperature, exhibit sulfur tolerance of 17.97wt%.