Colloidal Quantum Dots (QDs) acted as luminescent layer in light emitting device can be tuned across from visible to near-infrared spectrum by changing the size of QD, and QD-LED has a narrow bandwidth (Full-width at Half-maximum (FWHM) of the Electroluminescence (EL) peak of ～30 nm). Core–shell quantum dots (wavelength at 523nm and 608nm) with a CdSe core and a ZnS shell were used as emissive layers in the devices. Poly-TPD as Hole-transport Layer (HTL) and ZnO as Electron-transport Layer (ETL) were used in device. By fabrication of red and green emitting device based on quantum dots, we researched the feature of device which provides reference for quantum-dot-based LEDs used in the cockpit and medical apparatus. However, the brightness, efficiency and lifetime of QD-LED need to be improved to meet the requirements of commercialization in the near future.