An OLED display device and a manufacturing method thereof are provided. The OLED display device includes a base substrate, a plurality of OLED devices, and a plurality of spacers. A plurality of OLED devices are disposed on the base substrate. At least part of the OLED devices are provided with an inorganic layer on a side away from the base substrate. At least part of the spacers are distributed at the gaps between the OLED devices. The OLED display device can prevent a problem of degradation of display quality due to external impact.