The invention discloses a process for preparing organosilicon oil which contains hydrogen, in particular to a process for preparing organosilicon oil which contains hydrogen and methyl-phenyl silica chain link. The invention utilizes dimethyl silicone cyclic siloxane(Dn), polymethyl hydrogen cyclic siloxane(DmH), hybrid ring body of methyl and phenyl (DpPh), hydrolysis hybrid ring body of methyl and phenyl (D'qPh) to be polymerization reaction monomer, the process comprises adding the polymerization reaction monomer and blocking agent into organic solvent under the protection of N2 gas, controlling the reaction temperature and the reaction time, reacting under the function of catalyst, distilling to remove dissolvent in ordinary pressure after reacting, decompressing to withdraw low-boiling residue to get target product, purifying the product with activated carbon, and then the degree of purity of the product is high. The invention has the advantages of low cost, moderate contiditon, simple technology, simple and convenient operation and no pollution, and raw material are easily obtained, and the invention is suitable for industrialization. Products which are prepared by the invention have an excellent effect in the process of sealing and packing of LED.