The invention relates to a hybrid high-efficiency thermal-insulation material and a preparation method thereof. The preparation method comprises the following steps: by using a pretreated light-weight porous material as aggregate, an inorganic active material as an initiator, reactive polymer powder and white cement as gelling materials and ash calcium and gypsum powder as propping materials, mixing with fibers, a water repellent, cellulose ether, a surfactant and the like, stirring and dispersing to obtain the hybrid high-efficiency thermal-insulation material. The hybrid high-efficiency thermal-insulation material is composed of the following components in parts by weight: 20-40 parts of aggregate, 10-15 parts of inorganic active material, 5-10 parts of reactive polymer powder, 20-35 parts of white cement, 15-20 parts of propping material, 5-15 parts of fiber, 1-5 parts of water repellent, 0.1-0.5 part of cellulose ether and 0.5-1 part of surfactant. A right amount of water can be added into the material and stirred to obtain a paste, and the paste is directly spread onto the basal plane of the wall. The product has the advantages of low heat conductivity coefficient, high compression strength, favorable binding strength, thermal insulation, water resistance, fire resistance, crack resistance, no toxicity, environment friendliness, low shrinkage, simple construction technique, low unit area cost and the like, and is suitable for thermal insulation of various building external walls.