Abstract: At present, AI governance is gradually moving towards the era of legal governance, with obvious "national differences" characteristics. The most representative AI governance models are the EU's centralized governance model guided by ethics priority and the US's decentralized governance model guided by innovation priority. The study of the internal formation logic, characteristics and difficulties of AI governance models in the United States and Europe is of great benefit to the reflection and construction of AI governance systems in line with national conditions. The article compares and analyzes the differences of AI governance system between the United States and the European Union from five aspects: governance concept, governance structure, governance subject, governance intensity and governance dilemma. On this basis, it discusses the general issues and principles that should be paid attention to during the construction of the national AI governance system, such as paying attention to the tension between path dependence and model transplantation, balancing the relationship between "development" and "ethics", etc.