This book applies the concept of mechanism design to the field of inter-ethnic politics. From the perspective of institutional mechanism design, it studies the political practice of dealing with inter-ethnic relations in various countries, and explores the social effects of these systems and their relations through the analysis of the mechanism of the system and its design gist and process of the multinational countries in the contemporary world, including China, dealing with domestic national relations, tolerating differences in internationality, coordinating interests and identifying differences, and thus exploring the systems, methods and ways that have universal value for dealing with national problems in multinational countries, to promote the reform and innovation of the country’s political system, and promote national unity and social harmony in multinational countries.