A blue organic electroluminescent device, comprising: a substrate; an anode layer provided on the substrate; an anode modification layer provided on the anode layer; a hole transporting-electron blocking layer provided on the anode modification layer; a hole-dominated light-emitting layer provided on the hole transporting-electron blocking layer; an electron-dominated light-emitting layer provided on the hole-dominated light-emitting layer; a hole blocking-electron transporting layer provided on the electron-dominated light-emitting layer; a cathode modification layer provided on the hole blocking-electron transporting layer; and a cathode layer provided on the cathode modification layer; characterized in that the electron-dominated light-emitting layer is composed of an organic sensitising material, a blue organic light-emitting material, and an electron-type organic host material; the organic sensitising material is one or two selected from tris(acetylacetonate)phenanthroline thulium and tris(acetylacetonate)phenanthroline dysprosium; and the blue organic light-emitting material is one or more selected from bis((3,5-difluoro-4-cyanophenyl)pyridinato)picolinate iridium, bis(2,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate iridium, tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2') iridium,, bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium, tris[(2,6-diisopropylphenyl)-2-phenyl-1H-imidazol[e]iridium, tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C2')iridium, tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C2')iridium, bis(1-phenyl-3-methylimidazolin-2-ylidene-C,C2')(2-(2H-pyrazol-3-yl)-pyridine)iridium, bis(1-(4-methylphenyl)-3-methylimidazolin-2-ylidene-C,C2')(2-(2H-pyrazol-3-yl)-pyridine)iridium, bis(1-(4-fluorophenyl)-3-methylimidazoline-2-ylidene-C,C2')(2-(2H-pyrazol-3-yl)-pyridine)iridium, bis(1-(4-fluorophenyl)-3-methylimidazoline-2-ylidene-C,C2')(2-(5-trifluoromethyl-2H-pyrazol-3-yl)-pyridine)iridium, tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C2')iridium, bis(1-(4-fluorophenyl)-3-methylimidazoline-2-ylidene-C,C2')(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium, bis(1-(4-methylphenyl)-3-methylimidazolin-2-ylidene-C,C2')(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium, and tris(phenylpyrazole)iridium, the electron-type organic host material is one or more selected from 2,6-bis[3-(9H-9-carbazoyl)phenyl]pyridine, 1,4-bis(triphenylsilyl)benzene, 2,2'-bis(4-(9-carbazoyl)phenyl)biphenyl, tris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane, 1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene, 1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, and 9-(8-diplienylphosphoryl)-dibenzo[b,d]furan-9H-carbazole, the organic sensitising material is 0.1 wt%-0.5 wt% of the electron-type organic host material. a substrate; an anode layer provided on the substrate; an anode modification layer provided on the anode layer; a hole transporting-electron blocking layer provided on the anode modification layer; a hole-dominated light-emitting layer provided on the hole transporting-electron blocking layer; an electron-dominated light-emitting layer provided on the hole-dominated light-emitting layer; a hole blocking-electron transporting layer provided on the electron-dominated light-emitting layer; a cathode modification layer provided on the hole blocking-electron transporting layer; and a cathode layer provided on the cathode modification layer; the electron-dominated light-emitting layer is composed of an organic sensitising material, a blue organic light-emitting material, and an electron-type organic host material; the organic sensitising material is one or two selected from tris(acetylacetonate)phenanthroline thulium and tris(acetylacetonate)phenanthroline dysprosium; and the blue organic light-emitting material is one or more selected from bis((3,5-difluoro-4-cyanophenyl)pyridinato)picolinate iridium, bis(2,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate iridium, tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2') iridium,, bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium, tris[(2,6-diisopropylphenyl)-2-phenyl-1H-imidazol[e]iridium, tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C2')iridium, tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C2')iridium, bis(1-phenyl-3-methylimidazolin-2-ylidene-C,C2')(2-(2H-pyrazol-3-yl)-pyridine)iridium, bis(1-(4-methylphenyl)-3-methylimidazolin-2-ylidene-C,C2')(2-(2H-pyrazol-3-yl)-pyridine)iridium, bis(1-(4-fluorophenyl)-3-methylimidazoline-2-ylidene-C,C2')(2-(2H-pyrazol-3-yl)-pyridine)iridium, bis(1-(4-fluorophenyl)-3-methylimidazoline-2-ylidene-C,C2')(2-(5-trifluoromethyl-2H-pyrazol-3-yl)-pyridine)iridium, tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C2')iridium, bis(1-(4-fluorophenyl)-3-methylimidazoline-2-ylidene-C,C2')(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium, bis(1-(4-methylphenyl)-3-methylimidazolin-2-ylidene-C,C2')(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium, and tris(phenylpyrazole)iridium, the electron-type organic host material is one or more selected from 2,6-bis[3-(9H-9-carbazoyl)phenyl]pyridine, 1,4-bis(triphenylsilyl)benzene, 2,2'-bis(4-(9-carbazoyl)phenyl)biphenyl, tris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane, 1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene, 1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, and 9-(8-diplienylphosphoryl)-dibenzo[b,d]furan-9H-carbazole, the organic sensitising material is 0.1 wt%-0.5 wt% of the electron-type organic host material.