For a long time，the U.S. is the most popular country for international students to study abroad since it attracts students from all over the world with its high-quality education，good social development environment and leading role in the field of technology. After Donald Trump took office as the president of the United States，a series of changes have been taken place in the international student，employment，and immigration policies，resulting in a reduction in the number of international students in the United States. Although the number of people obtaining H-1B visas has continued to rise steadily，the passing rate of H-1B visa applications has shown a downward trend. However，based on the number of Chinese students who applied for and obtained the H-1B lottery qualifications，the willingness of Chinese students to work in the United States is generally stable. After the outbreak of COVID-19 pandemic in 2020，the Trump administration has stepped up its efforts to prohibit some Chinese students from entering the United States，and suspended most of the visa applications such as F-1 and H-1B，which brings a huge uncertainty to Chinese students who want to study and work in the United States. It is recommended that relevant Chinese government departments and institutions increase the protection of the rights and interests of Chinese students in the U.S. to ensure that Chinese students in the U.S. can successfully complete their studies；at the same time，actively promote Sino-U.S. academic exchanges and cooperation to ease tensions in Sino-U.S. relations；Based on the influence of COVID-19 pandemic and the tightening of immigration policies，it is recommended that the Chinese government seize the opportunity of talent return，further improve the employment and entrepreneurship system and talent evaluation mechanism for overseas students returning to China，and create good conditions for overseas students to return to China.