Abstract: The effect of nitrogen supplying intensity and ratio of coke powder and bottom blowing gas flow rate on gasification dephosphorization are studied,in combination with thermodynamic analysis of gasification dephosphorization for top and bottom combined blowing converter in this paper.The result shows that it is feasible to use carbon-based dephosphorizer to reduce P₂O₅ in slag at steelmaking temperature.and it is more reasonable to choose coke powder as reducing agent.In order to achieve the gasification dephosphorization rate more than 36%,the nitrogen supplying intensity,ratio of coke powder and bottom blowing gas flow rate should be controlled at 4.5~6.5 m³/ （t·min）,8%~12% and 280~400 m³/h respectively.