A concurrent mixed-methods study was conducted to examine the factors influencing COVID-19 prevention and control behaviors and to describe the management model implemented in Mae Sai District, a Thai–Myanmar border community, from June 2022 to May 2023. Mae Sai reported 21,890 confirmed cases and 12 deaths during the pandemic, underscoring the severity of the outbreak and the need for an effective local management model. Quantitative results indicated that attitudes, social support, participation, and service accessibility significantly influenced preventive behaviors among the general public. Among volunteers, perception and attitude were also significant, whereas only social support and participation were influential among government officials. The management model identified in this study demonstrated effectiveness through its coordinated multisectoral operations, high community compliance, and rapid cross-border communication. The model consisted of five components: emergency preparedness drills, organizational management through district and subdistrict disease control centers, a unified incident command system led by the district chief, coordinated domestic and international operations, and enforcement of control measures at formal checkpoints, natural crossings, and within communities. Successful implementation depended on strong collaboration among government agencies, volunteers, private organizations, local communities, and partners in Myanmar. This framework may serve as a practical guideline for managing other communicable diseases and enhancing preparedness for future health threats.