The present disclosure relates to display technologies, and particularly discloses an organic electroluminescent device. This organic electroluminescent device includes a light-emitting layer, the light-emitting includes an exciplex composed of a donor molecule and an acceptor molecule, and a wide band gap material for increasing the inter-molecular spacing between the donor molecule and the acceptor molecule. According to the device of the present disclosure, the degree of orbital overlap of HOMO and LUMO of the formed exciplex and the singlet-triplet energy level difference can be reduced, the reverse intersystem crossing rate (kRISC) of the exciplex host can be increased, the Föster energy transferred to the guest molecule can be enhanced, and the efficiency and the lifetime of the device can be improved.