The present disclosure relates to a high-selectivity hydrophilic electrode for electrochemically extracting lithium and a preparation method thereof. The preparation method includes the step of carrying out surface coating modification on an electrode active material by using polydopamine. The interception of impurity ions is achieved by utilizing the advantages, which polydopamine has, of preferentially accumulating and transporting lithium ions, thereby improving the selectivity of the electrode active material on lithium. In the pulping process of an electrode adsorption material, a hydroxyl-containing polar hydrophilic organic polymer compound is introduced to perform blending modification, thereby improving the hydrophilicity of a binder polyvinylidene fluoride (PVDF). In addition, pore formation via inorganic salts is combined with a drying mode of “low temperature-high temperature” so that the “porous-microcrack” morphology is formed on the electrode, thereby improving the mass transfer effect of the solution inside the electrode. The preparation method of the electrode disclosed by the present disclosure has the characteristics of simplicity, practicability, environmental friendliness, low cost and the like, and is easy for industrial production.