There are several reasons why civilization is the core of ethnic conflicts in the post-cold war era: 1 After the Cold War, people's loyalty to ideology declined and their loyalty to civilization increased. 2. The development of regional economy and the emergence of regionalism after the Cold War: 3. With the development of information and communication technology, the earth is becoming a global village, and the relationship between people is getting closer and closer, which is followed by the emergence of tension between people; 4. The end of the East-West confrontation after the Cold War filled the power vacuum of religion and civilization. Huntington believes that after the Cold War, the decisive factors of the world pattern are six civilizations, namely Confucian civilization, Japanese civilization, Indian civilization, Islamic civilization, Western civilization, orthodox civilization, and possibly Latin American civilization and African civilization. The conflict between these civilizations will be the core of the future world. There are two ways to conflict between civilizations: the fault zone conflict between neighboring countries of different civilizations or between different civilizations in the same country; The post-cold war world is multipolar, and the reconstruction of the world order must be based on civilization. Huntington's theory of clash of civilizations has a great influence on the western theory of state relations. It analyzes the present situation of state relations from a novel perspective, but its defects and deficiencies have attracted criticism from many scholars from the beginning. Just as war cannot be avoided between the same civilization, there may not be conflicts between different civilizations, and the theory of clash of civilizations has serious defects from theory to practice.