European politics experienced challenges and fluctuations in 2019，while new opportunities emerged. After the 9th European Parliament election，new European Union leaders took office and opened a new political cycle. Brexit is entering a new phase，uncertainty is not entirely eliminated while certainties are increasing. In the meanwhile，European politics is still persecuted by political polarization and differentiation，and Brexit continues to stir up the UK-EU relationship. Considering that the post-Brexit era and political polarization are intertwined，European politics is at a crossroads.