Migration is a historical issue that exists along with the evolution of humanity. Since 2015, Europe has witnessed a strong wave of illegal migrant arrivals from the Middle East, Africa, and Asia, creating an economic, political, security, and social crisis in the region. This article is devoted to discussing how the migrant crisis has affected regional security and the reasons why the policy responses of the EU and member states are effective enough to handle this phenomenon. First, the author presents an overview of the migrant crisis in Europe since 2015 by indicating statistical information of the number of migrants coming to Europe each year, and demonstrating the motivations of their choices. Second, four negative impacts of the migrant crisis on the security of Europe are pinpointed. Third, the article seeks to deliver an in-depth analysis of European countries’ policy responses to this problem, which opens up wholly new prospects, raises new questions, and presents new efforts towards the promotion of global and regional integration, cooperation, and unity. On this basis, the author personally comes up with some policy implications for Vietnam in dealing with the migration issue. To achieve these research objectives, the author mainly uses popular research methodologies in social science and international relations in particular to find out answers to the raised questions.