Since the modern nation-state appears,the analysis on the relationship between ethnic identity and national identity has become a conundrum within the domain of politics,whereas the present mainstream viewpoints and the political practice have turned it into a dual dilemmas further which seems to have no solutions. To solve it,this paper redefines the relationship between ethnic identity and national identity based on the analysis of their types of mutual relations,explores effective solutions to standardize and coordinate the relations of nation-state commencing from the exposition of nation-state identity status in a multiethnic country. Eventually, it reveals a new type of identity,i.e. the identity of national community,a new vision of political ethics for the harmonious development of all nations.