The purpose of this study is to analyze how China will use the three-warfare strategy and suggest implications for Korean security. China's three-warfare strategy is to establish a strategic advantage by securing international influence and legitimacy by utilizing public opinion warfare, psychological warfare, and legal warfare in military and non-military activities. Korea's security is located between the United States and China, and China is likely to increase its influence by utilizing domestic public opinion and division between Korea and the United States through the three-warfare strategy. Therefore, it is necessary to prepare a preparation strategy to prepare for China's three-warfare. The United States is actively responding by officially acknowledging the risk of China's three wars and reorganizing related organizations and systems, but the reality is that Korea is insufficiently prepared for this. Therefore, it is suggested that the government and national defense should study ways to prepare for the Three warfare of China and prepare preparations.