A series of organic light-emitting diodes (OLEDs) were designed and fabricated to further enhance electroluminescence (EL) performances of the green phosphorescent emitter bis(2',6'-bis(trifluoromethyl)-2,3'-bipyridine) tetraphenylimidodiphosphinate. 4,4',4″-Tri(9-carbazoyl) triphenylamine (TcTa) and 9,9'-(2,6-pyridinediyldi-3,1-phenylene)bis-9H-Carbazole (26DczPPy) were selected as host materials of light-emitting layers (EMLs) 1 and 2, respectively, because of their well-matched energy levels and high carrier mobility. In addition, the design of double-EMLs device structure helps to broaden the recombination of holes and electrons by the analysis of devices performance. Finally, the green OLEDs with turn-on voltage of 3.1 V, maximum brightness of 12600 cd/m ², current efficiency of 37.15 cd/A, maximum external quantum efficiency of 10.34%, and maximum power efficiency of 28.23 lm/W was obtained.