The invention discloses thermal-insulating transparent additional liquid silicon rubber and a preparation method thereof. The thermal-insulating transparent additional liquid silicon rubber consists of the following raw materials in parts by mass: 100 parts of vinyl silicon oil, 90-110 parts of a vinyl MQ silicon resin, 15-20 parts of hydrogen-containing silicon oil, 0.02-0.2 part of a copper-double-end carboxyl organo-siloxane coordination polymer, 0.05-0.2 part of 1-ethynyl-1-cyclohexanol and 0.1-0.4 part of a platinum catalyst. The thermal-insulating transparent additional liquid silicon rubber disclosed by the invention is excellent in thermal resistance, good in transparency, easily available in raw material, simple in machining process, convenient in large-scale production and wide in application prospect in the fields of electronic appliances, medical instruments and the like.