The purpose of this study is to conduct a comparative analysis on the mental health and health-related quality of life of the community residents who have been affected by the Sewol ferry disaster and to provide a basis for future aids for potential human-caused catastrophe. The study utilized the big data, Korean community health survey data of 3,632 (1,803 in 2018 and 1,829 in 2014) residents in Ansan and Jindo, a victimized community of Sewol ferry disaster, and compared the subjective level of health, amount of appropriate sleep, subjective stress level, stress consulting, depression, depression consulting, and health-related quality of life before and after the disaster. According to the findings, community residents who have been affected by the Sewol ferry disaster did not show any significant difference in terms of subjective health level, amount of appropriate sleep, subjective stress, and health-related quality of life. The study aims to serve as a foundational data for developing a prevention program or policy that aims to support future potential disasters by comparing the mental health and health-related quality of life of the victimized community before and after the disaster. The study suggests that the need for continuous monitoring of mental health and health-related quality of life of the victimized residents is significant, and further studies should be implemented in order to provide better supports for the local community.