AI Agent technology is different from traditional large language models in that it can make autonomous decisions, perform multi-step tasks, and sense the environment; thus, it is now changing the world of technology. The AI Agent will use the large language model in the scaffolding software to plan and carry out a series of tasks independently without continuous human intervention, and it can do more than just answer questions. The purpose of this architecture is dual-use, and it can be employed for civil and military applications; thus, the same framework of autonomous planning and tool invocation that has optimised commercial workflows can also be used in the military for command and control, intelligence analysis, autonomous weapons systems, etc. Therefore, the dual-use boundary is determined not by the category of goods but by how they are used and connected in the system; thus, the old way of classifying or declaring the end-use of goods is no longer effective. With the intensification of strategic competition between China and the United States and the changes in the economic security strategy of the European Union, many countries have begun to add artificial intelligence to the mandatory foreign investment security review. The Committee on Foreign Investment in the United States has expanded the scope of application for inbound investment under the Foreign Investment Risk Review Modernization Act, introduced the Outbound Investment Security Program to curb outbound investment in countries of concern, and by 2025, the National Security Presidential Memorandum will increase control over sensitive technologies such as artificial intelligence. The new Foreign Direct Investment Screening Regulation in the EU lists artificial intelligence, quantum technology and semiconductors as important areas to be monitored for all member states, and the EU has started to study the screening of outbound investments. China's Measures for the Security Review of Foreign Investment have covered significant amounts of information and key technologies in the field of information technology and core industries, but specific judgment criteria for the new form of technology, AI agents, have not been established. Building on the foundation of technological security paradox, this paper thinks that the commercial value of AI Agent technology is directly related to its autonomy, adaptability and generalisation ability; at the same time, these are also the reasons for concern. Based on the criteria and practice in the United States, the European Union and China, as well as through cases such as Shield AI, OpenAI and the merger of SpaceX and xAI, this paper introduces the three structural defects of the current review system. The first is the accuracy of technical identification; static classification cannot consider that the capability changes according to the application environment. The second is the coordination of norms, as the security of a country is increasingly used to achieve technological containment in the background of geopolitical competition. The third is dynamic adaptability; that is to say, with the exponential growth in agents' capabilities, the revision of review norms has been slow. A new hierarchical review model based on functions, rather than product labels, will be put forward in this paper. The five parts of the AI Agent model are Autonomy, Connectivity, Adaptability, Collaboration and Accumulation, and one of them has been assigned to each of the four risk levels. If any aspect reaches the third level, a deep audit will be conducted; if two or more aspects reach the third level or any single aspect reaches the fourth level, then strict measures will be taken. Some proposals for the construction and operation of the Chinese review system were also made in this paper, such as adding a particular review guide for AI agent technology, establishing a joint expert assessment team to conduct practical capability tests, and introducing a regular update mechanism for threshold parameters. By changing the focus of the review from what a technology is to what it can do, the model aims to provide a theoretical basis and an institutional reference for China to improve the judgment criteria for the civilian and military dual-use attributes of AI Agent technology in foreign investment security review.