With the increase of population mobility and the promotion of Intercultural interaction in college freshmen enrollment, cultural identity is more conducive to national unity, and national unity education emphasizes the identity of communities with common language, history, region, culture, customs, and habits. This paper expounds the realistic challenges of cultural pluralism to China's national education and national security under the background of globalization, introduces the basic characteristics of multiculturalism, and deeply studies the cultural diversity of China's ethnic regions and the integrated development of the Chinese nation. In view of the current situation in China, the impact of cultural identity on political, economic, cultural, religious, and ecological construction has introduced in detail. The economy promotes people's livelihood, the party's leadership stabilizes the social environment, and the cultural interaction of ethnic areas promotes cultural identity in college freshmen enrollment and national unity. Finally, the system construction from national cultural identity to Chinese cultural identity based on the theory of national identity is proposed. There are problems and infl uencing factors in the process of college freshmen enrollment, and corresponding suggestions for improvement have put forward. In addition, it should have pointed out that if cultural identity in college freshmen enrollment can have eff ectively used in the study of national unity education, it is necessary to draw on the relevant results of Intercultural perspective psychology.