In the second half of the 20th century, the demand for scientific and technological talents in the United States was constantly changing. With higher requirements putting forward for the cultivation, use and introduction of talents, the relevant policies of the United States government were adjusted accordingly. Combined with the characteristics of the times, the development of American scientific and technological talents in this period can be divided into three stages characterized by sudden advance, fluctuation and prosperity. The reasons why the United States has become a great power of science and technology talents include the leading role of national intervention, the whole-length awareness of innovation and crisis, the great attraction of higher education and the huge social and economic value created by foreign talents. The problems in the development of American scientific and technological talents include the demand for national defense talents crowding out the demand for talents in economic and social construction, gender and minority discrimination, and excessive dependence on foreign scientific and technological talents.