The invention discloses a glass adhesive and a preparation method thereof. The glass adhesive is prepared from the following components: ethylene carbonate, zinc oxide, ethylene carbonate, curing agent, coupling agent, liquid nitrile rubber, promoter, phenolic resin, silicon dioxide, and emulsified silicon oil. The preparation method comprises the steps of putting the ethylene carbonate, ethylene carbonate, liquid nitrile rubber and coupling agent into a reaction kettle, mixing uniformly, and performing temperature-programmed reaction to obtain a reactant I; then mixing the reactant I, the zinc oxide, curing agent, promoter and phenolic resin, and then performing temperature-programmed reaction in vacuum condition, so as to obtain a reactant II; and finally mixing the reactant II with the silicon dioxide and the emulsified silicon oil, and mixing and polishing by a colloidal mill so as to obtain the glass adhesive. The glass adhesive provided by the invention has high bonding performance and low temperature resistance.