The invention discloses a heat insulation coating, and belongs to the field of building coatings. The heat insulation coating aims at solving the problem that a heat insulation coating in the prior art is thick in coating layer and is unsuitable for a facing layer of a building external wall. The heat insulation coating is characterized by being prepared from low-density hollow glass microspheres,hydrophobic emulsion, a water repellent, nanosilicon dioxide, a foaming agent, an air entraining agent, elastic emulsion, a thickening agent and grapheme. The heat conductivity coefficient of the coating is lowered to 0.030 W / (m K), the coating can be used in cooperation with primer and a reflective heat insulation surface paint layer, a coating with the low thickness is scraped in batch, and theexcellent heat insulation effect can be obtained. The invention correspondingly discloses a preparing method for the heat insulation coating, the heat insulation coating prepared with the method is suitable for scraping in batch or spraying or napping construction, and has the advantages of being high in bonding strength, good in waterproof performance and excellent in anti-cracking and heat insulation performance. The invention also discloses a heat insulation system with the heat insulation coating, and the heat insulation system has the advantages that the heat insulation system can be used for a building external wall / internal wall, the heat insulation effect is good, and energy saving and environmental protection effects are achieved.