The Party-state system has been formed and developed during China's long-term revolution, construction and reform practice, and it has played a presupposed role in China's administrative state construction. As the most important political force, the Communist Party of China has always been in the core leadership position in the construction of China's modern state, and it is deeply embedded in the modern state governance system, forming a “two-in-one” relationship within the state power system. The construction of China's administrative state under the Party-state system takes the Party's leadership as the prerequisite, the institutionalization of public power as the basic path, and the rationalization of bureaucratic system as the carrier. This construction not only fully demonstrates the political accountability and the political wisdom of a mission-oriented political party, but also shows the bureaucratic characteristics and professional advantages of the rational bureaucracy.