The invention discloses a mixed slag smelting reduction production and thermal refining method, and belongs to the field of non-blast furnace iron smelting and comprehensive utilization of resources. The method comprises the following steps: 1) an iron-contained material and a reducing agent are added in mixed slag of blast furnace slag and molten steel slag for heating to reach a molten state; and oxide gas is sprayed for iron smelting by smelting reduction to treat most iron-contained material; and 2) an iron component, a calcium silicon component and a phosphorus component in the mixed slag are separated and recovered according to a reaction device. After smelting reduction, the reduced slag can serve as a cement additive, a cement regulator, a cement clinker or a cement clinker with high production additional value, so that the method realizes efficient comprehensive utilization of the resources, and is a new smelting reduction iron making method. The method uses smelting reduction of the mixed slag for production of pig iron or steel and phosphorus-enriched phases and thermal refining, is short in reaction time, high in metal recovery rate, low in production cost, high in raw material adaptability, high in handling quantity, environment-friendly and high in economic benefit, and can effectively achieve the goal of efficient recycling of metallurgic resources and heat energy.