Abstract: As one of the most transformative technological directions between 2025 and 2026, AI Agent is reshaping the boundaries of human-computer interaction and promoting the leap of artificial intelligence from passive response to active service. By constructing core modules such as perception, planning, decision-making, and reflection, combined with tool calling capabilities and hierarchical memory management mechanisms, AI Agent has acquired the abilities of multi-step reasoning and environmental interaction, becoming a core application form for the implementation of technologies in the large model era. Represented by frameworks such as OpenClaw, a new generation of AI Agent frameworks has broken the application limitations of traditional intelligent tools by virtue of the automatic operation capability in desktop environments driven by natural language instructions, promoting the paradigm shift of intelligent systems from tools to personal assistants, and demonstrating the development trends of continuous service, personalized adaptation and gradual evolution into user digital avatars. However, with the improvement of AI Agent’s autonomous decisionmaking authority and the expansion of environmental control scope, its security risks have been increasingly prominent, including issues of internal cognitive bias such as intent misunderstanding and perception hallucination, as well as external malicious threats such as prompt injection, privacy leakage and backdoor attacks, making it a new high-risk application form. This paper systematically reviews the developmental trajectory of AI Agents from tool calling to intelligent personal assistants, analyzes their key principles and technical evolution, and explores security risks within their interaction mechanisms alongside future research directions.