Abstract: Aiming at preheater system build-ups and high SO3 content clinker when firing high-sulfur coal in the cement precalciner kiln, chemical reactions occurring during the sulfur cycle in the pyroprocessing zones were illustrated. The influence of oxygen content, temperature, retention time in the kiln, reducing atmosphere and other factors on the sulfur volatilization was analyzed and corresponding solutions were proposed to reduce it. Based on the theoretical analysis, application techniques of high-sulfur coal presented by our company were introduced from three aspects, including sulfur-fixing technology, precalciner system design and operation control.