Abstract: Extremism is a distorted religious doctrine or other performance or implementation of inciting hatred, discrimination, violence and other advocacy of ideas and behaviors, including extreme nationalism, extreme environmentalism and extreme animal protectionism, anti-abortion extremism, etc., but religious extremism is the most harmful one. Religious extremism has the characteristics of political purpose and antisocialism, alien negativity, violence, non religious nature, etc. It originated from illegal religious activities, firmly believing in terrorism, developing terrorist organization members, collaborating with foreign hostile forces, and so on. All countries should hit and curb all forms of extremism to root out its ideological basis.