The invention relates to a preparation method of porous mullite-corundum perovskite loaded La1-xKxCo0.7Fe0.3O3 (x is equal to 0.2 to 0.8). The preparation method comprises the following steps: preparing a porous mullite-corundum material by taking bauxite and diatomite as raw materials through carrying out wet milling, filtering, drying and stirring, additionally adding a binding agent, a dispersant, a foam stabilizer and a foaming agent, and molding, drying and sintering; then loading perovskite on a porous mullite-corundum carrier by adopting a vacuum impregnation and calcining method to prepare a porous mullite-corundum perovskite loaded La1-xKxCo0.7Fe0.3O3 material. The preparation method has the characteristics of simple process, short production period, high efficiency, stable product quality, low cost and the like; the porous mullite-corundum perovskite loaded La1-xKxCo0.7Fe0.3O3 material can be produced and prepared according to requirements and the preparation method has a relatively good industrial utilization prospect.