An optical brightness enhancement structure and a manufacturing method thereof and an electronic device are provided. The method for manufacturing an optical brightness enhancement structure includes: providing a light-transmissive carrier, and forming a buffer layer on a first surface of the light-transmissive carrier; forming a plurality of microstructures for converging light on a surface of the buffer layer away from the light-transmissive carrier; and surface energy of each of the microstructures is greater than surface energy of the buffer layer.