The invention provides an electrode and a preparation method thereof and a dry etching device of the electrode. Through separate design of the electrode, the electrode includes an electrode substrate and a protection layer attached on the upper surface and side surfaces of the electrode substrate. The protection layer has a structure which matches the electrode substrate. When reactants and by-products attached on the protection layer are to affect etching of a glass substrate after the electrode works for a period of time, the protection layer can be partly replaced. Ceramic cleaning or stripping maintenance is carried out without disassembly of the electrode so that high-intensity electrode maintenance work is prevented. At the same time, the protection layer is designed into a film layer with elasticity so that friction and collision of the glass substrate and protrusions are reduced and pressure damage defect of the back part of the glass substrate is prevented.