Since Biden administration’s inauguration at the beginning of 2021，the U.S.-EU relations have been repaired to some degree，but their bilateral strategic competitions in the fields of economy and security have not been mitigated. In the meantime，the painful transition period of Brexit ended and the UK finally completed its withdrawal from the EU. Pushed by the profound “trust deficits” in U.S.-EU and EU-UK relations，the UK gradually approached the United States and alienated itself from the European Union. In the fields of economy，more improvements have been made on the U.S.-UK bilateral cooperation for joint research and development on emerging technologies and advanced manufacturing. At the same time，the Johnson’s cabinet has also been learning from the United States during its legislative work for a more sophisticated system of investment screening and review structure. In the fields of security，the UK has even been more apparently tilting itself toward the United States. It has accepted the U.S.policy framework and strategic arrangement，supported and followed the American Indo-Pacific strategy in full effort，and has actively participated in the “U.S.-UK-Australia Indo-Pacific Security Partnership”. On the other hand，however，it indicates disinterest in the EU’s proposal that UK shall become part of the “Common European Security System”. At present，the UK attempts to take full advantage of the policy-making discretions and the international maneuvering space newly created from its formal exit from the EU，endeavoring to strengthen its connections with the United States and shift its focus of foreign economic relations to the Indo-Pacific region，which will inevitably bring more uncertainties to the China-UK relations.