As an important group of minerals, sulfides, formed by the combination of one or more metals with sulfur, have great economic importance as a major source of most metals, and the research on sulfur isotope fractionations in sulfides constitutes a focus of discussion in the stable isotope geochemical field. Being an important geochemical tracer, the sulfur isotope fractionation in sulfides can be used to analyze the ore-forming process and the ore-forming material source. Based on the authors' up-to-date research, this paper dealt with the theoretical calculation of sulfur isotope fractionation in sulfides and has reached the conclusion that at present the improved method can be used to approximately calculate the thermodynamic isotope fractionation factors of sulfur in sulfides of geochemical interest.