The legibility of characters is a crucial aspect of display design, yet it has been less explored in vibration environments. Using a within-subjects design, this study examined the impacts of different font design parameters (i.e., font size of 12, 14, and 16 pt.; stroke width of 1:6 and 1:10) on the legibility of Chinese characters under vibration. Twenty participants engaged in character-search tasks within pseudo-texts. The total search time and the correct response rate were used to measure the legibility. The results indicated that although font size and stroke width significantly affected the legibility of Chinese characters under vibration, the effects observed differ from those in static conditions. In vibration environments, the legibility of the 14 pt. font size was better than that of the 16 pt. font size, which in turn was better than that of the 12 pt. font size. Besides, characters with thicker stroke width (1:6) were more legible than characters with thinner stroke width (1:10). The combination of the 14 pt. font size and the 1:6 stroke width provided the best legibility. These findings could offer valuable suggestions for the font design of Chinese characters in vibration environments to enhance the legibility.