Abstract: The application of hydrate method to the removal of carbon dioxide in blast furnace gas was proposed. Tetra-n-butyl ammonium bromide (TBAB) was selected as the thermodynamic promoter. Chen-Guo hydrate thermodynamic model was applied to calculate and predict the pressure of gas hydrate in TBAB solution. The model was used to calculate the pressure of hydrate containing part of blast furnace gas +TBAB, with the average relative error between the calculation result and experimental value in the literature being about 3 %~16 %. The average relative error between calculation results of the hydrate pressure of CO₂+CO+N₂+H₂+water of different concentrations and values in the literature was 7.5 %~11.7 %. Comparing the experimental data of blast furnace gas +TBAB measured by pressure exploration with the calculation results, we found that the average relative error was 16.6 %, which indicated that the model could predict the phase equilibrium condition of blast furnace gas in TBAB solution.