The present disclosure provides a light emitting diode, a method of preparing the same, and a display device. The light emitting diode includes an anode, a quantum dot light emitting layer, an electron transport layer, a cathode, and a transition layer located between the electron transport layer and the cathode, the cathode including a transparent conductive oxide material, and a material of the transition layer having a work function WF between an LUMO of a material of the electron transport layer and a work function WF of a material of the cathode.