In the complex background of the wide spread of COVID-19，the intensifying strategic games among great powers and the U.S. presidential campaign，the Trump administration attempted to reduce negative effects of the pandemic upon the U.S. military on the one hand，and on the other，focused more on great power competition，speeding up the adjustment of its regional strategy and military deployment，strengthening the network of global alliance partnership，innovating its combat theories，and promoting the development of its weaponry in an intelligent，miniaturized and unmanned way. All these actions above are aimed at maintaining asymmetric competitive advantage of the Trump administration against great power competitors，so as to defend the U.S.global leadership.