Abstract: The effects of different conditions on the equilibrium species about high-phosphorus hematite were investigated by Fact Sage6.4 thermodynamic analysis software. And some experiments were made to verify the thermodynamic analysis data. The results show that the existence forms of gas phosphorus were different at different temperatures,a rise of temperature enhances the phosphorus removal. The right amount of SiO₂ concentration can reduce the onset temperature of carbothermic reduction of fluorine calcium phosphate,when the SiO₂ concentration is high,the phosphorus removal were restricted by the produced silicate melts. When the C concentration is low,phosphorus is still contained in the fluorine calcium phosphate,when the C concentration is high,phosphorus is reduced to form FeP. Cl₂ can react with P₂ to produce PCl₃,when the temperature is low,the dephosphorizing product is PCl₃,when the temperature is high,the first dephosphorizing product is P₂,changes the dephosphorizing product to produce PCl₃ need higher concentration of Cl₂. Experimental verification was conducted by using simultaneous thermal analyzer,the experiment results are in good agreement with those of the thermodynamic analysis.