The authors focuses on the inflow of the foreign human resource in science and technology into U.S after World War Ⅱ, trying to look at the nature of the problem by the phenomenon of the inflow of talent, and drilling down the national policies and mechanisms. After listing the data of foreign technology professionals, the authors specifically analyze the U.S. policies about immigration, talents, higher education, investment in science and technology and other aspects, and sum up the advantages of U.S to attract foreign talents. The specific research objects of the article are technology professionals, such as scientists and engineers as well as the graduate students of higher education. Through the historical analysis of the inflow of the technology talents, the authors sum up the historical experience and lessons of U.S as a country with large human resources in the world, and recognize the multi-polar flow trends and characteristics of global talents flow in the new period. <<