In order to understand the difference of process energy consumption between limestone slagging and lime slagging in steelmaking, experiments with limestone as slagging agent were carried out in 300 t converter, and the energy consumption was compared from the angles of gas, steam recovery and steel slag production. The results showed that comparing the steelmaking process with limestone as slagging agent to that with lime as slagging agent, on the premise of reducing the scrap steel addition by 71.6 kg per ton steel, the recovery of gas (CO) increased by 21.5 m³per ton steel, the recovery of steam increased by 28.0 kg per ton steel, and the steel slag decreased by 31.4 kg per ton steel. From the energy consumption of lime fluxes, the energy generated by gas and steam recovery, and the energy consumption of steel slag, the average energy consumption of the two processes was -38.9 kg per ton steel and -23.9 kg per ton steel, respectively. The former saved energy 23.3 kg per ton steel at most and 9.5 kg per ton steel at least and 15.0 kg per ton steel on average compared with the latter.