The invention relates to an embossed flattened rigidity-reinforced electrolytic electrode plate and a preparation method thereof, the electrolytic electrode plate comprises an electrode plate, an embossed groove is arranged on the surface of the electrode plate, and forms a concave convex pattern to improve the electrode plate surface strength and bending resistant ability. The embossed groove is composed of a plurality of transverse embossed grooves and oblique embossed grooves to form a structure shaped like a Chinese character mi, and raised structure composed of an upper triangular convex block and a lower triangular convex block is formed on the electrode plate. The beneficial effects of the embossed flattened rigidity-reinforced electrolytic electrode plate are that: aiming at the electrode plates of different types, reinforced stripes with different specifications and different shapes are designed, through embossing and shaping of the reinforced stripes, the electrode plate rigidity is greatly enhanced, the internal stress is eliminated, the objective of improving the electrode plate surface flatness, reducing the bending deformation, and enhancing the electrode plate bending resistant ability can be achieved, anode and cathode short circuit phenomenon in the process of electrolysis due to deformation can be avoided, the power consumption in the electrolysis or plating process can be effectively reduced, at the same time, cathode product quality is improved, the labor intensity is reduced, and production efficiency is improved.