An OLED panel and a manufacturing method thereof are provided. The panel includes a substrate, a plurality of OLED devices disposed on the substrate and an auxiliary cathode. The OLED devices include a cathode and have light emitting areas respectively. The auxiliary cathode is disposed on the cathode of the OLED devices in electrical contact with the cathode and the auxiliary cathode is at least partially located in the light emitting areas of the OLED devices. A material of the auxiliary cathode is a transparent conductive material.