A light-emitting device (10) includes an anode (101) and a cathode (102), and a light-emitting unit (104) arranged between the anode (101) and the cathode (102). The light-emitting unit (104) includes at least two light-emitting layers (5) and a charge generation layer (6) arranged between two adjacent light-emitting layers (5). At least one light-emitting layer (5) includes a first light-emitting sub-layer (51) and a second light-emitting sub-layer (52), the first light-emitting sub-layer (51) is closer to the anode (101) than the second light-emitting sub-layer (52). The first light-emitting sub-layer (51) includes a first host material and a first guest material; the second light-emitting sub-layer (52) includes a second host material and a second guest material; a triplet energy level of the first host material is greater than that of the second host material, and triplet energy levels of the host materials are greater than those of the guest materials.