In the era of digital economy, artificial intelligence infrastructure has become the core support for the development of artificial intelligence, driving the reshaping of the global AI industrial ecosystem and the expansion of the competition arena among major countries. This article focuses on the study of key elements of AI infrastructure construction, systematically reviews the practical experiences and policy measures of developed countries in deploying and applying AI infrastructure from the perspective of the foundation layer, model layer, application layer, and policy layer, and analyzes the challenges China faces in AI infrastructure construction. It provides theoretical and practical basis for China to enhance innovation efficiency, clarify capability boundaries, and regulate technological risks in the field of artificial intelligence. Finally, the article puts forward policy suggestions around basic technologies, model architectures, application integration, and policy guarantees.