The invention relates to a flexible photo-anode for a flexible dye-sensitized solar battery and a preparation method thereof. The flexible photo-anode comprises a flexible transparent conductive substrate and a dye-sensitized nano porous semiconductor film, wherein the flexible transparent conductive substrate is formed by arranging metal grids on a flexible transparent substrate, spreading a bulking agent in meshes of the grids and then overlaying a high molecular conductive polymer film. By spreading the bulking agent in the meshes to flatten the metal grids and overlaying the high molecular conductive film on the metal grids to connect the metal grids into an organic conductive whole, the nano porous semiconductor film prepared on the flexible transparent conductive substrate can be flat and compact. Electrons produced by the battery which is assembled by the prepared flexible photo-anode can be fast transmitted to the external circuit to form a photoelectric current, and the battery has the advantages of high photoelectric transformation efficiency and long service life.