The invention relates to a high-reflection radiation-resistant fiber heat insulation material, which comprises single-layer fiber tissue paper, wherein the framework is aluminum silicate fiber, and the high-reflection radiation-resistant fiber heat insulation material comprises the following components in percentage by mass: 35-45% of the aluminum silicate fiber with an average fiber diameter of 1-3mu m and normal fiber diameter distribution, 10-20% of rutile titanium dioxide, 10-15% of short whisker potassium hexatitanate, 10-15% of an adhesive and 5-10% of a dispersant. The high-reflection radiation-resistant fiber heat insulation material is formed by superposing the single-layer tissue paper, the aluminum silicate fiber framework is distributed in the horizontal direction, the high-reflection radiation-resistant fiber heat insulation material is free of penetrating vertical fiber, the overall thermal conductivity of the material is reduced, the mass ratio of titanium dioxide to potassium hexatitanate in the single-layer fiber tissue paper is 1-1.5: 1, the mass ratio of aluminum silicate fiber to titanium dioxide is 1.5-2: 1, the aluminum silicate fiber skeleton is distributed in the horizontal direction, titanium dioxide and potassium hexatitanate particles are distributed in a gradient manner in the tissue paper, a multi-layer reflection barrier is formed in the fiber heatinsulation material, the overall reflectivity and the radiation resistance can be effectively increased, and the material can be applied for a long time in a high-temperature and high-radiation environment.