International situation and global challenges has become increasingly severe from 2019 to 2020. The Sino US relations were not eased by the conclusion of the first phase agreement of trade negotiation at the end of 2019. On the contrary，China US relations accelerated to deteriorate in 2020 due to the impact of the covid-19 pandemic. 2020 is the year of the US presidential election which attracts worldwide attention. The pandemic has added great uncertainty to the election itself. International and global issues，such as arms control and strategic stability，relations between Russia and the west，public health governance，climate change，and cyber security，are also affected to varying degrees by the pandemic，making the already intractable challenges more complex. Think tanks and research institutes paid close attention to these new situations and changes and put forward their analysis and suggestions. In order to follow up the latest researches of top think tanks on related topics and better understand the relevant hot issues，this article takes the top international think tanks in “2019 Global Go To Think Tank Index Report” as the research objects，and reviews the related researches and reports published by these think tanks in the past year.