The COVID-19 pandemic has exposed significant deficiencies in global community infectious disease prevention and control systems. In the post-pandemic era, optimizing community-level prevention and control mechanisms has become a top priority for public health governance. This study adopted a mixed-methods approach, integrating quantitative surveys and qualitative interviews to investigate the operation status, existing problems, and optimization needs of community infectious disease prevention and control systems in 12 cities across 5 countries. A total of 3,620 community residents and 482 public health workers were surveyed, and 60 in-depth interviews were conducted with community managers and medical staff. The results showed that the main challenges faced by community prevention and control systems included insufficient professional staffing, inadequate resource allocation, weak public health awareness among residents, and poor coordination between multiple departments. Based on the results, this study proposed a multi-dimensional optimization framework covering organizational structure, resource allocation, service supply, and public participation. Practical verification in 4 pilot communities confirmed that the optimized system significantly improved the efficiency of infectious disease monitoring, early warning, and response. This study provides important theoretical and practical references for strengthening community public health capacity and building a resilient infectious disease prevention and control system in the post-COVID-19 era.