The invention belongs to the technical field of rubber asphalt pavement materials and discloses a stabilizer for rubber asphalt and a modification method of the rubber asphalt. The stabilizer for the rubber asphalt is prepared from the following raw material components in parts by weight: 15 to 25 parts of sodium soyate, 10 to 20 parts of sodium polyacrylate, 10 to 20 parts of sodium silicate and 10 to 20 parts of sodium gluconate. The sodium soyate, the sodium polyacrylate, the sodium silicate and the sodium gluconate serve as the raw materials of the stabilizer for the rubber asphalt for the first time, so that a thickening effect is achieved, the steric hindrance among the components of the rubber modified asphalt is enlarged, and the dispersity and the stability of the rubber power in the asphalt are improved.