The 1965 immigration law changed the traditional pattern of American immigration law, Asia and Latin America have replaced Europe as the main immigration areas. Mexican immigrants, with unique characteristics and are different from the immigrants from other countries, have gradually become the focus of attention. After 9. 11, the discussions about the Mexican immigrants among American scholars have gone from the socioeconomic level to the national security level. This paper analyzes the influence of the Mexican immigrants on America's economic, political, social and cultural security.