The invention relates to an interface pretreatment liquid for a silicon-oxygen pre-lithiation negative electrode as well as a preparation method and application of the interface pretreatment liquid. The interface pretreatment liquid comprises 0.1%-10% of solute and 90%-99.9% of solvent, the solvent is one or more selected from N-methyl pyrrolidone, ethylene carbonate, fluoroethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, gamma-butyrolactone, methyl formate, ethyl formate, methyl acetate, ethyl acetate, ethyl propionate, propyl propionate, ethyl butyrate, propyl butyrate, dimethyl sulfoxide, ethylene glycol dimethyl ether, 1, 3-dioxolane, dipolyethylene glycol dimethyl ether and dimethyl thionyl ether; and the solute is selected from one or more of lithium polysulfide, aluminum iodide, aluminum bromide, lithium nitrate and copper nitride. The solvent can fully infiltrate the internal pores of the lithium-rich negative plate and the surface of the negative active material, and the solute can react with the negative material, so that the stability of the SEI membrane is improved, and the first charge-discharge efficiency and long-term cycle performance of the battery are synergistically improved.