The invention discloses a preparation process of a silicification-free rubber plug. The preparation method comprises the steps of compounding rubber, flaking rubber, molding, volcanizing and molding,cutting, washing and drying, and packaging, and further comprises the steps of sequentially coating a dimethylsiloxane prepolymer solution and a polyvinylidene fluoride resin dispersion on the surfaceof washed and dried rubber plug, and drying and curing coating layers, wherein the dimethylsiloxane prepolymer solution is mainly prepared from the following components in parts by weight: 1-5.5 parts of dimethylsiloxane prepolymer, 0.2-0.5 part of silane crosslinking agent, 100 parts of organic solvent A, and the polyvinylidene fluoride resin dispersion is mainly prepared from polyvinylidene fluoride resin emulsion containing 5-15% of solid and silicon rubber catalyst. The cured rubber plug has a compound coating layer, low surface friction coefficient, good anti-ultraviolet performance, chemical resistance and anti-aging performance, and the silicification process in preparation of the rubber plug is prevented.