Yan Fu put forward the slogan of "saving the country" in the article "On Saving the Country". He translated the theory of evolution and put forward the social evolutionary thought of "natural selection" and "survival of the fittest", which inspired people's sense of crisis and national consciousness. He shouted loudly that all ethnic groups in the world are competing for survival, and the Chinese nation is no exception. If China can't strengthen itself, it will perish and lose its right to national survival.