The invention relates to a preparation method for novel splicing accelerant. The preparation method comprises the following steps: adding triallyl isocyanurate, a noble metal catalyst and solvent intoa reaction still; after temperature is raised and stirring is carried out, slowly dripping the mixed liquid of trialkoxysilanes, hydrogen-terminated silicone oil and solvent into the reaction still;after dripping is finished, carrying out heat preservation reaction; cooling to 60 DEG C; dripping the mixed liquid of allyl glycidyl ether and solvent into the obtained mixture; after heat preservation reaction, filtering, and carrying out rotary evaporation to remove the solvent and a low-boiling-point substance, and a target product, namely the splicing accelerant, is obtained. The splicing accelerant synthesized with the above method simultaneously contains three polar groups, including alkoxy, epoxy group and hexacyclic isocyanurate, and the splicing performance of organosilicone adhesivefor different base materials can be greatly accelerated. The novel splicing accelerant has good compatibility with an organosilicone system, is especially suitable for an organic silica gel [such asLED (Light Emitting Diode) silica gel] system of optical application and has good compatibility and splicing acceleration function with the organic silica gel system.