Belite sulfoaluminate cement was prepared by the segmental calcination system using phosphogypsum （PG） reduced by sulfur gas as the sole calcium oxide source. The mineral phase composition and hydration properties were studied by X-ray differaction and Fourier infrared spectrum. The results show that main mineral phases of the clinker are Ca₄Al₆（SO₄）O₁₂（C₄A₃S¯），Ca₂SiO₄（β-C₂S） and Ca₈Fe₄Al₄O₂₀（C₄AF）， with small amounts of gehlenite（C₂AS） and alpha'-Ca₂SiO₄·0.05Ca₃（PO₄）₂（α'-C₂S）. When the calcination temperature and calcination time are increased， the content of C₄A₃S¯ increases. However， above 1 300 °C and 90 min， the formation of C₄A₃S¯ is adversely affected. Excessive calcination will reduce the strength of the clinker at each age， which is disadvantageous for its early strength development and is beneficial to its later strength development.