In recent years，European countries are facing more and more serious security and defence challenges. On the one hand，the financial crisis and European sovereignty debt crisis lead to a sharp shrink of the European defence budgets and，consequently，deeply affected the European Union’s ambition to act as a global security provider. On the other hand，the shift of US strategic priorities，withdrawing from European neighborhood towards the Asia-Pacific，makes the Europeans concern themselves about security；at the same time，it means that they must uphold more burden-sharing. In addition，many structural problems in defence sector are also pressing for a quick solution. In recent years，European countries are reinforcing their defence cooperation，especially the defence summit，which was held at the end of 2013，indicating to some degree that the Europeans take the cooperation more seriously than ever. But within quite a long time，because of the absence of the common strategic culture and core system arrangement，the defence cooperation on the EU level will not proceed very fast，but the tendency is irreversible.