The invention relates to an iron-containing solid byproduct of iron making by smelting reduction and a manufacturing method thereof. The byproduct comprises the following components in percentage by weight: 20-75% of dry basis of gas mud, 20-75% of dry basis of iron ore minus undersize powder, 1-5% of dedusting powder dry basis, 10-30% of binding agent and 8-15% of water. The byproduct and the manufacturing method provided by the invention finally realize the reutilization of smelted ironmaking sludge, can manufacture the iron-containing product conglomerations for smelting reduction, reduce the molten iron cost, and reduce environmental pollution.