The factors that influenced the public’s intention to take preventive measures and precautions during the COVID-19 pandemic are worthy of investigation as they could inform future prevention and intervention efforts during public health crises. Our study utilizes the cognitive mediation model as a theoretical framework to examine the variables that impact individuals’ willingness to undertake preventive behaviours. An online questionnaire survey, conducted randomly and representing the whole country, was employed to examine the impact of guidance, news attention, news elaboration, and knowledge on citizens’ inclination to adapt preventive measures during a pandemic. The results show that guidance has a positive impact on news attention and elaboration. Knowledge and behavioural intentions are positively impacted by news attention and elaboration, while behavioural intentions are positively impacted by knowledge. Based on the results derived from structural equation modelling, we emphasize that only joint efforts by policymakers, media service platforms, and the public can boost citizens’ willingness to take precautions against an epidemic.