The invention discloses a thermal shock resistant high-refraction LED packaging glue composition and a preparation method thereof; the LED packaging glue composition is prepared from component A and component B at a weight ratio of 1:1; the component A is prepared from, by weight, 25-35 parts of methyl phenyl vinyl silicone resin, 10-20 parts of methyl phenyl vinyl silicone oil, 0.1-0.3 part of a catalyst, and 0.01-0.03 part of a heat resistant; the component B is prepared from, by weight, 5-15 parts of methyl phenyl vinyl silicone resin, 30-45 parts of methyl phenyl hydrogen-containing silicone resin, 0.02-0.1 part of an inhibitor, and 0.5-3 parts of an adhesion promoter. The invention belongs to the technical field of LED packaging and provides the LED packaging glue composition, having the excellent properties, such as adhesion, thermal shock resistance, permeability, refractivity and hardness, and capable of meeting the requirements of high-power LED packaging.