A display device and an OLED display panel thereof. The OLED display panel includes a non-transparent display area including first OLED pixels, a transparent display area including second OLED pixels, a display driving chip, a first gate driving circuit group. For a same of image, a pulse width of the second gate driving signal for the second OLED pixels is substantially the same as a pulse width of the first gate driving signal for the first OLED pixels; and intersection points of a boundary line and a pixel row where the first OLED pixels in a specified row are located falls within a range of intersection points of the boundary line and a corresponding pixel row of the second OLED pixels.