Abstract: Desulphurizer is one of the key factors in the field of desulphurization technology. In this paper, the influence of several additives on the desulphurization effect of calcium-based compounds and the mechanism were analyzed based on a lot of experiments. Different kinds of sulfur-fixing agents based on CaCO3 were prepared by inputing some single additive, some mixed additives and reformed by some chemical solutions. The desulphurization rate of these agents was studied with ZCS-1 intelligent sulphur determination. Some highly efficient agents and CaCO3 were calcined, and their physical characteristic were studied with PoreMaster-60 mercury porosimeter. Some reformed agents by some chemical solution after being added certain additives had better results at high temperature. The sulfur-fixing efficiency of the best one could reach as high as 50% (Ca/S=1.5) at 1 100 ℃. Its physical and sintered characteristic at high temperature were improved. After reformed with aliphatic acid and being added some additives, the porosity of CaCO3 increases from 15.57% to 34.93% while its surface area increases from 14.52 m2/g to 19.94 m2/g.