A display device and a manufacturing method thereof are provided. The display device includes a circuit substrate, multiple light-emitting elements and a packaging material. The circuit substrate includes a first surface, a second surface opposite the first surface, and multiple through slots penetrating through the first and second surfaces. The through slots each are in a stepped form, and the circuit substrate is divided into a chip mounting area, multiple anodes, and a common cathode. The light-emitting elements include multiple light-emitting elements mounted on the circuit substrate along a straight line and electrically connected with the anodes respectively through wires. The packaging material covers the circuit substrate, the light-emitting elements and the wires. The display device has an excellent performance while achieving a small size.