In order to study the effect of lump ore ratio on the softeningmelting properties of ironbearing charge under different blast conditions, the temperature and gas content under three blast conditions were simulated and the effect of lump ore ratio on the softeningmelting properties of ironbearing charge was studied using a hightemperature droplet furnace, then the optimization of the comprehensive burden structure was analyzed. The results showed that with the oxygenenriched and humidified blast conditions, the hydrogen content increased, the maximum pressure drop in the furnace was effectively reduced, the smelting zone was narrowed, and the gas permeability in the furnace was improved. Under the blast condition of oxygenenriched and humidified, although the increase of the ratio of lump ore will lead to the increase of the maximum pressure drop and the softmelting temperature interval in the blast furnace, the absolute value of the maximum differential pressure was still much smaller than the maximum differential pressure under the reference condition, and the width of the softeningmelting temperature interval was also less than the width under the reference condition. It can be seen that with the proportion of lump ore appropriately increased under oxygenenriched and humidified blast conditions, the softeningmelting properties of the comprehensive burden were still superior to that on the reference condition, and the production cost of the blast furnace can be reduced, which was an effective optimization for the burden structure.