In the context of the “dual carbon” strategic goal,mineralization fixation technology has received increasing attention as an important CO₂ emission reduction pathway. As a calcium-based industrial solid waste rich in alkaline substances,steel slag has become an ideal and inexpensive raw material for CO₂ fixation. In this paper,the effects of different liquid-solid ratios,temperature and pressure on carbon sequestration rate and the optimal process conditions are studied by low liquid-solid ratio wet process mineralization method,and the phase composition and microstructure of steel slag and carbon sequestration products are analyzed by XRD and XRF. The results show that the low-liquid-solid radio wet process mineralization method synergistically realizes cost-effective steel slag solid waste recycling and CO₂ storage by reducing water consumption and energy consumption and enhancing the mass transfer efficiency of the reaction. Affected by the thickness of the water film,there is an optimal value of liquid-solid ratio. Under the conditions of 100 ℃,0. 85 MPa, and 450 r/ min,when the liquid-solid ratio is increased from 0. 2 mL/ g to 0. 4 mL/ g,the carbon sequestration rate is increased from 11. 8% to 21. 2% . However,when the liquid-to-solid ratio is further increased to 1 mL/ g,the carbon sequestration rate is decreased to 9. 3%,indicating that an appropriate thickness of the water film is beneficial for the mass transfer process. The carbon sequestration rate shows an increasing trend with rising temperature and pressure. For a liquidsolid ratio of 0. 6 mL/ g,when the temperature is increased from 25 ℃ to 100 ℃,the carbon sequestration rate is increased from 4. 8% to 20. 9%;when the pressure is increased from 0. 85 MPa to 2. 85 MPa,the carbon sequestration rate is increased from 20. 9% to 27. 6% . However,excessively high temperatures and pressures can lead to a decrease in the increase in carbon sequestration rate as well as an increase in energy consumption. In summary,under the optimal process combination of reaction temperature of 100 ℃,reaction liquid-solid ratio of 0. 6 mL/ g,reaction pressure of 2. 85 MPa, reaction time of 1 h and stirring rate of 450 r/ min,the carbon sequestration rate of steel slag is 27. 6%,that is,the maximum carbon sequestration is 276 g/ kg.