The invention discloses a high-
transmittance OLED display panel for under-screen
fingerprint identification and a preparation method thereof. The high-
transmittance OLED display panel comprises a substrate; sequentially forming a buffer layer, a low-temperature
polycrystalline silicon layer, a gate
insulation layer, a gate layer, an interlayer
insulation layer, a source and drain
electrode layer, a flat layer, an
anode layer, a pixel definition layer, a spacer layer, a light-emitting layer, a
cathode layer, a packaging layer, a touch layer and a reflection reduction layer on the substrate; an
oxide semiconductor layer is arranged between the gate insulating layer and the gate layer, and the source-drain
electrode layer is connected with the
oxide semiconductor layer and the low-temperature
polycrystalline silicon layer; the
anode layer is connected with the source-drain
electrode layer; the pixel definition layer and the spacer layer are respectively connected with the
anode layer; the light-emitting layer at least partially covers the anode layer; the
cathode layer at least partially covers the light-emitting layer, the pixel definition layer and the spacer layer. According to the
OLED display panel, except for the driving TFT, the other TFTs are
oxide semiconductors, and the
transmittance of the oxide semiconductors is far higher than that of low-temperature
polycrystalline silicon, so that the transmittance of the OLED display panel is improved.