The US-Australia relationship has maintained close ties since World War II，and Australia is one of the important alliances of the United States in the Asia-Pacific region.Since Trump took office，some new changes have taken place in the US-Australia relationship，showing certain practicability and asymmetry.Under the perspective of the “Indo-Pacific” strategic concept，the US and Australia have a geopolitical framework in Indo-Pacific and cooperation will be carried out；the United States and Australia will further deepen the cooperation in military and national defense；In terms of diplomacy，Australia actively responds to the United States and adopts a containment attitude and measures against China；on the economic front，Australia adopts a bet on both sides.