Brexit has ushered in a new era of British space exploration. After Brexit，and especially after being excluded from the EU’s Galileo navigation system，the UK has adjusted its space strategy，resumed its space launch program，and sought to become an important participant and leader in the new space era. By coordinating the space sector，industry and science，the UK government has abandoned the traditional dual space development system，which relies on Europe and the US，and shifted to a “three-wheel” system that enhances the country’s independence，strengthens commercial cooperation with the European Space Agency，and deepens space militarycooperation with the US and other allies. The UK-US space military alliance is an important pillar of the UK’s space power construction after Brexit. It can make up for the decline in space power caused by Brexit and enhance space deterrence，high-level visits and space military exercises being the main support for the construction of bilateral military alliance. At present，the UK’s space development is hampered by the weak competitiveness of the space industry chain，lack of sovereignty and autonomy in space security，and imbalance in space balance. The UK’s accelerated entry into and participation in space affairs has also had a multi-dimensional impact on space governance.