Disclosed are an epitaxial wafer and a display device that includes a display substrate, a first sub pixel unit and a second sub pixel unit. The first sub pixel unit has a first luminous area, and the second sub pixel unit has a second luminous area different from the first luminous area. The first sub pixel unit and the second sub pixel unit belong to the same color type and are located in different pixel units. The first sub pixel unit is a sub epitaxial structure emitting light within a first photoluminescent wavelength, the second sub pixel unit is a sub epitaxial structure emitting light within a second photoluminescent wavelength, and the first photoluminescent wavelength is different from the second photoluminescent wavelength. The difference between electroluminescent wavelengths of the first sub pixel unit and the second sub pixel unit is less than or equal to 2 nm.