High-power LED packaging adhesive composition

The invention discloses high-power LED packaging adhesive composition which is prepared from the following raw materials in parts by weight: 10-90 parts of phenyl vinyl silicon resin, 0-5 parts of MDQ resin, 0.002-0.005 parts of a platinum catalyst, 15-40 parts of high-phenyl hydrogen-containing silicone oil or 20-50 parts of high-phenyl hydrogen-containing silicone resin and 0-3 parts of a tackifier, the phenyl vinyl silicon resin, the MDQ resin and the platinum catalyst form a component A; the high-phenyl hydrogen-containing silicone oil or the high-phenyl hydrogen-containing silicone resin and the tackifier form a component B; the vinyl content ratio of the component A to the component B is 1.1-1.4. A preparation method for the high-power LED packaging adhesive composition comprises the following steps: mixing the component A with the component B, defoaming, putting a defoamed mixture into a drying oven with the temperature of 80 DEG C for 2 hours, heating to 150 DEG C, keeping the temperature for 3 hours, and cooling to the room temperature to obtain the high-power LED packaging adhesive composition. The high-power LED packaging adhesive composition has the refractive index of more than 1.52 and the light transmittance of more than 95% before and after being cured, and is good in mercurochrome test effect, high in shore hardness and suitable for high-power LED packaging.