The synthesis of ultra-low R/Si methyl silicone resin to methyl diethoxy silane, methyl triethoxy silane and ethyl orthosilicate as starting materials, after hydrolysis condensation is methyl silicone resin ethanol solution. Ethanol is a polar solvent, both reaction raw material alkoxy silane hydrolysis to produce ethanol or with the solvent of ethanol, must contain trace moisture content, and cannot be ruled out in polar solvent trace moisture will seriously damage of silica dielectric properties, as through wave material for this high through wave organic silicon resin must employ a nonpolar solvent. The hydrolysis and condensation reaction of ultra-low R/Si methyl silicone resin is very sensitive and fast. If ethanol is removed by distillation and then converted to non-polar solvent, the silicone resin will be prematurely crosslinked to discard, and the ultra-low R/Si methyl silicone resin prepared by conventional technology will not be dissolved in non-polar solvent. Which should be taken to solve the key problem, special technical measures, the alkoxy silane monomer hydrolysis initial stage, try to build "a particular reaction environment", the hydrolysis product "in situ to form" soluble in nonpolar solvent resistance, and in the process of subsequent condensation reaction, should continue to control the reaction products maintain can be soluble in nonpolar solvent, Under these conditions, the reaction by-product ethanol was gradually removed and replaced by a non-polar solvent. Through such a complicated special synthesis process, the ultra-low carbon silicone resin which could be dissolved in a non-polar solvent was prepared.