“Autonomous Strategy” is one of the most important development strategies of the EU, as well as a natural trend of the European integration. For several hundred years, Europe had been trapped in the chaos of war caused by the striving for hegemony between the great powers. It was not until the end of World War II that a half-century peace and development has been achieved in Europe. However, due to the bi-polar contest during the Cold War, Europe had never walked out the shadow of war. The EU has only gained new development space after the end of the Cold War. Especially after the Trump Administration announced the "America First" policy, Europe realized the necessity to launch an autonomous development strategy in the newly emerging international pattern. After the outbreak of the Russia-Ukraine Conflict, Europe has to choose to strengthen security cooperation with the US, which, however, does not signify its abandoning of the "autonomous strategy". On the contrary, the EU has demonstrated a greater degree of realistic flexibility and maturity in the new environment. After having experienced a series of shocks including the debt crisis, Brexit and the Russian-Ukraine conflict, the European integration will be further enhanced and deepened by the EU's focusing on "autonomous strategy".