Prefabricated construction, known for its efficiency and ecofriendliness, presents new safety management challenges due to its unique characteristics, such as the use of large components and frequent lifting operations. The presence of safety vulnerability in this construction method is influenced by various factors, and Internet of Things (IoT) technologies hold substantial promise in mitigating this vulnerability. In this article, we adopt partial least squares structural equation modeling to comprehensively scrutinize the relationships among various factors and their impacts on the formation of safety vulnerability. Furthermore, a two-mode social network analysis is conducted to quantitatively analyze the mitigation effects of IoT technologies on safety vulnerability. The results reveal that workers’ unsafe behaviors, high work pressure, and inadequate construction supervision significantly contribute to the formation of safety vulnerability in prefabricated construction. The study further finds that IoT technologies play a crucial role in mitigating safety vulnerability by improving compliance with safety regulations and fostering safety commitment among managers. Notably, sensors and auto-ID technologies emerge as prominent IoT technologies with substantial reduction effects on safety vulnerability. These findings strongly advocate for the widespread adoption of IoT in prefabricated construction to enhance safety performance.