From the end of the 20th century to the beginning of the 21st century, contemporary American ideology has been polarized. The original dualistic ideology is becoming increasingly polarized. Democratic-based left-wing liberalism strengthens free trade, feminism, legalization of same-sex marriage, egalitarianism, globalization, which is a strong contrast with the formation of republican-based right-wing conservatism. The polarization of right-wing conservatism is manifested in propositions such as trade protection, white supremacy, anti-homosexuality, anti-immigration, and anti-globalization. The polarization of contemporary American ideology is distributed in various fields, including democratic socialism and conservatism in the economic field, and polarization in the field of political party, elitism, and the mass. The focus of polarization is still culture. In various fields such as race, morality, religion, education, and language, the polarization of ideology is very serious. At the same time, this polarization is also unfolding at the level of global exchanges, forming an all-round picture of ideological polarization. The polarization of contemporary American ideology has very complex roots, and the interactions among ideologies is one of the important influencing factors.