Abstract: In the long-process steelmaking system, the proportion of carbon emissions is extremely high. Therefore, the development of green and low-carbon technologies in ironmaking is crucial for emission reduction. In allusion to the significant heat loss during the transportation of hot metal ladle without cover insulation, the composition of such heat loss and the corresponding actual carbon emissions were analyzed. A comparative analysis was carried out on the energy-saving and emission-reduction effects of hot metal ladle for heat compensation and ladle covering for heat preservation. The results showed that both methods could increase the molten iron temperature by more than 30 ℃. Empirical applications of these two methods and the achieved carbon emission reduction results indicated that applying cover insulation during hot metal ladle empty period was the most effective measure, which was more conducive to emission reduction. Moreover, it significantly reduced heat loss and carbon emissions with almost no external energy supply. Compensatory heating served as a supplement and auxiliary measure to cover insulation, could realize the self-circulation of blast furnace gas within the traditional blast furnace ironmaking process, which was of great significance for carbon emission reduction.