A method for fabricating a fingerprint sensor includes providing a base substrate including a plurality of pixel regions, forming a sensing dielectric structure on the base substrate in the plurality of pixel regions, and forming a sensing connection structure in the sensing dielectric structure. The sensing dielectric structure exposes the sensing connection structure, and the sensing connection structure is connected to the base substrate. The method also includes forming a plurality of electrode plates on surfaces of the sensing dielectric structure and the sensing connection structure, forming a plurality of protrusions on surfaces of the electrode plates by performing a bulging treatment process on the plurality of electrode plates, and forming an insulation medium structure on the plurality of electrode plates.