Abstract: The COVID-19 pandemic poses a representative societal risk that demands an interdisciplinary and cross-sectoral response. The virus threatens the health of individuals through various environmental transmission pathways, and individuals can resist and mitigate the transmission risk by increasing their risk perception and adopting preventive behaviors. This study surveyed 2,950 participants through an online questionnaire at four critical stages: the early pandemic (March 2020), the Omicron variant surge (December 2020), the Delta variant surge (August 2021), and the Omicron subvariant surge (January 2022). The research aimed to analyze changes in individuals' awareness of virus transmission risks in different environmental pathways, their risk perception (defined as concern levels on risk transmission pathways), preventive behaviors, and community-level prevention measures. Findings revealed that among three types of transmission paths, participants had the highest awareness of the risk of droplet and aerosol transmission, and the lowest awareness of the risk of waterborne transmission. Individuals' overall level of risk awareness increased throughout different pandemic stages, but risk perception showed a slight decline over time. Meanwhile, individual risk perception increased with stricter preventive measures. Higher risk perception was associated with more frequent adoption of preventive behaviors, indicating that risk perception positively influenced risk preventive behaviors. However, its impact varied dynamically over time. Future pandemic prevention strategies should emphasize the virus transmission risk of diverse transmission pathways, particularly waterborne risks, and adjust dynamically across different stages to enhance individual risk perception and effectively encourage individual risk response behavior.