The invention discloses a novel rubber activator and a preparation method thereof. The rubber activator particularly comprises 20 to 80 percent of aromatic group-containing formic acid type metal salt and 20 to 80 percent of zinc oxide, wherein the aromatic group-containing formic acid type metal salt is mixed with the zinc oxide at normal temperature and the two are stirred for 5 to 15 minutes at the rotation speed of between 2,000 and 3,500rpm. Compared with the prior art, the problems of high zinc content and high heavy metal element content in the zinc oxide can be effectively solved, density is reduced, dispersibility is improved, and the novel rubber activator improves rubber tensile property, broken chain elongation rate and rubber cross-linking effect.