Since the beginning of the 21st century, a new wave of populism has swept across Europe and America. The left-wing populism based on "economic anxiety" and the right-wing populism based on "identity anxiety" are surging together in Western politics and impinging on the political order of the world. The populists of the developed countries in Europe and America show their basic traits of national populism in the face of immigration and globalization. With the help of new media and Internet, populists’ voices fill the whole society assisted by the "echo chamber effect" and "polarization effect", thus becoming a structural problem that disturbs the world order.