Provided are an OLED screen and a manufacturing method thereof. The OLED screen has a display area and a peripheral area located on a left side and a right side of the display area. The OLED screen comprises: a back plate, a polyimide layer, an array layer, an OLED layer, a thin film encapsulation layer, a polarizer and a cover plate stacked in order; a mirror layer is disposed between the thin film encapsulation layer and the polarizer, and at least a portion of the mirror layer in the peripheral area is not covered with the polarizer; a portion of the cover plate in the peripheral area is not covered with ink. When the organic light emitting diode screen is lit, the light emitted by the organic light emitting diode layer can be transmitted out of the peripheral area to achieve a frameless display effect.