The present invention provides an OLED display device and a manufacturing method thereof, in which a planarization layer (5) of a white sub pixel zone (40) is made to have a thickness greater than the thickness of a planarization layer (5) of the other sub pixel zones so as to increase the vertical distance between bottom wiring (2) and a first electrode (6) in the white sub pixel zone (40) thereby compensating the problem that the vertical distance between the bottom wiring (2) and the first electrode (6) of the white sub pixel zone (40) is relatively small resulting from lacking of a filter in the white sub pixel zone (40) and preventing the occurrence of shorting or over current between the first electrode (6) and the bottom wiring (2) of the white sub pixel zone (40). The manufacturing method is simple and easy to perform and may prevent the occurrence of shorting or over current between the first electrode and the bottom wiring of the white sub pixel zone thereby enhancing yield rate of manufacture of the OLED display device.