In order to investigate the influence of the primary spectrum of a display device on the color discrimination difference of observers with normal color vision, five display devices with different red, green and blue color primary spectral energy distributions are selected. Based on the 5 color stimuli recommended by CIE, 30 observers aged from 20 to 27 with normal color vision are organized to carry out the color-matching experiment based on these five display devices. Meanwhile, the 108 color-matching functions (CMFs) are used for the computational simulation of the color-matching process, and the calculation results are compared with the color-matching experimental ones. The influence of different display devices on the discrimination of observers is quantified by the metamerism index. It is found that the simulation results are well consistent with the color-matching experimental ones. With the 285 CIELAB color difference data acquired from the color-matching experiment based on the selected four display devices to be matched and the target display device, the maximum of 9.59 and the minimum of 3.89 as for the metamerism index are obtained. The primary color spectrum of a display device has a strong influence on the observer metamerism and the influence of a red color device is weaker than those of yellow and blue ones.