The excellent optoelectronic characteristics of quantum dots, such as high quantum yield, wide absorption range, narrow emission spectrum and adjustable emission wavelength, make them show great application prospects in displays. Quantum dots synthesized by chemical-solution methods not only have the advantages of a simple preparation process and low cost, but also can be used to achieve high-resolution displays in various ways. The excellent electroluminescence and photoluminescence of quantum dots make them play an important role in the research of displays. Electroluminescent quantum-dot light-emitting diodes have achieved a rapid development in the research of material synthesis and device structure, which provides a foundation for the realization of commercial displays. The displays using the photoluminescence of quantum dots have attained a wider color gamut and presented a richer visual effect. This paper introduces the characteristics, electroluminescence and photoluminescence of quantum dots, and their applications in displays, summarizes the research status of quantum-dot devices, and analyzes the existing problems in the development of quantum-dot devices.