The present invention provides an OLED display panel. The display panel includes a plurality of sub-pixels arranged in an array. Each of the sub-pixels comprises a base substrate, a TFT layer, a flat layer, a first electrode, a pixel defining layer, a light emitting layer, a transparent second electrode, and an encapsulation layer. A portion of at least one of the flat layer and the pixel defining layer is formed by a black shielding material. The OLED display panel can be prevented from reflecting ambient light without improving the light extraction efficiency, thereby improving the viewing experience of the OLED display panel by the arrangement of a portion of at least one of the flat layer and the pixel defining layer is formed by a black shielding material.