The present invention provides an OLED display device, which includes: a substrate (1), a plurality of pixel zones arranged in an array on the substrate (1), each of the pixel zones comprising a pixel electrode (2), an organic light-emitting layer (3), and a common electrode (4) that are sequentially stacked on the substrate (1), and a pixel separation layer (5) including a plurality of openings, the openings being each delimited and circumferentially surrounded by a pixel separation layer sidewall (51), each of the openings corresponding to one of the pixel zones. The pixel separation layer (5) is formed of an inorganic material. The pixel separation layer sidewall (51) includes, arranged from top to bottom, a first curved section (511), a linear section (512), and a second curved section (513), so as to overcome a deterioration issue of the organic light-emitting layer (3) caused by the pixel separation layer sidewall (51), prevent the organic light-emitting layer (3) and the common electrode (4) from breaking at a site corresponding to the pixel separation layer sidewall (51), prevent shorting between the common electrode (4) and the pixel electrode (2), which are the cathode and anode of the OLED display device, and improve displaying performance.