The invention provides a color filter structure and an OLED display panel. The color filter structure includes a base layer, a color filter, a black matrix, a protective film, and a transparent conductive film, wherein the color filter includes nanoparticles. The OLED display panel includes a base substrate, a TFT structure, a color resistor retaining wall, a light-emitting layer, a pixel definition layer, a black retaining wall, a cathode layer, the color filter structure, and an encapsulation layer, wherein a height of the color filter structure is slightly lower than or equal to a height of the black retaining wall.