With the widespread application of IoT (Internet of Things) technology in smart homes, the security protection of systems has received more attention. In response to the problems of incomplete vulnerability detection and outdated defense mechanisms in traditional methods, this article proposed an efficient and comprehensive vulnerability detection and defense framework. By periodically scanning all terminal devices in the smart home system through edge devices, known vulnerabilities in the system were identified. Through edge computing technology and AI (Artificial Intelligence) algorithm detection, lightweight distributed defense mechanisms were deployed between intelligent devices to ensure that when an attack occurred, it can quickly respond locally and reduce the system response time. The experimental results showed that all devices in the edge computing-based scheme had a high coverage rate of more than 90%. In terms of the average response time, the edge computing defense framework combined with AI algorithm was 7.2 s, far lower than the traditional defense methods. The experimental results prove that this research is efficient in improving vulnerability detection and defense response.