Selective solar heat absorption coating with low emission ratio and preparation method for selective solar heat absorption coating

The invention discloses a selective solar heat absorption coating with a low emission ratio, sequentially comprising an anti-reflection layer, a main absorptive coating and a high-reflection substrate layer from top to bottom, wherein the high-reflection substrate layer is prepared by a large-area electron beam evaporation coating technology; evaporation materials used in the evaporation coating technology are aluminum, copper or silver. The invention further discloses a preparation method for the selective solar heat absorption coating with the low emission ratio. According to the selective solar heat absorption coating with the low emission ratio and the preparation method for the selective solar heat absorption coating with the low emission ratio, an infrared high-reflection substrate layer of the selective solar heat absorption coating is prepared by the large-area electron beam evaporation coating technology, the thickness of the infrared high-reflection substrate layer can be increased, and the selective solar heat absorption coating can easily have a lower infrared emission ratio through the thicker coating. The selective solar heat absorption coating is less influenced by base material conditions, and has the lower infrared emission ratio at the same time.