Herein, a linear hydrogen cross-linker with a high hydrogen content was proposed in the study. The hydrogen-containing di-phenyl silicone oil (HDPSO) was fabricated by non-hydrolytic sol-gel reaction and ring-opening polymerization. After raw materials were mixed with vinyl base polymer, the cured sample showed ultra-high hardness (~ 92 shore D), refractive index (~ 1.542 at 633 nm), and transparency (~ 92.6% at 450 nm). After lighting for 168 h at room temperature, the samples showed no yellowing phenomenon and the lumen depreciation was only 4.9%. The samples demonstrated outstanding reliability compared to other commercialized silicone materials. The HDPSO is a promising cross-linker candidate for reliable high-performance LED encapsulantion.