An array substrate and a manufacturing method thereof, and a display device are provided. The array substrate includes: a plurality of pixel units arranged in an array, each of the pixel units including a first transparent electrode and a color filter unit opposite to each other. A first insulating layer is disposed between the first transparent electrode and the color filter unit, a protrusion is provided between adjacent first transparent electrodes, and a vertex of the protrusion is higher than an upper surface of the first transparent electrode.