This study examined the influence of eHealth literacy on Chinese individuals’ attitudes towards post-COVID-19 vaccination and explored methods to address obstacles related to eHealth literacy that could affect their comprehension and willingness to get vaccinated. In 2022, a web-based cross-sectional survey was conducted to assess the vaccination-related knowledge, attitudes and intentions of 950 participants. Vaccination knowledge was established by employing validated measures and conducting a Mokken scale analysis. Causal-directed acyclic graphs were used to illustrate the current comprehension of the correlation between eHealth literacy and the desire to receive vaccinations. This study utilised causal mediation and multiple linear regression analysis to determine the relationships between eHealth literacy, vaccination knowledge, vaccination willingness and subjective health status. The primary finding of this study was that an individual’s comprehension of vaccination was a robust indicator of their inclination to receive vaccination. Moreover, eHealth literacy has an indirect effect on the propensity to get vaccinated by enhancing one’s understanding of vaccines. This study emphasises the significant role of eHealth literacy in enhancing vaccination awareness and willingness, particularly among Chinese adults with poorer health in the post-COVID-19 period. The results affirm the efficacy of employing eHealth technologies to bolster immunisation initiatives, amplify vaccine consciousness, and promote compliance. Moreover, this study emphasises the significance of additional research to assess and record the function of eHealth literacy in immunisation practices.