As unmanned aerial vehicle (UAV) become increasingly sophisticated, the range of potential applications is expanding, creating a corresponding need for navigation systems that are both safe and reliable. In light of the aforementioned considerations, this study proposes a UAV navigation system that integrates the 3D A* algorithm with digital twin technology, with the aim of exploring the potential applications of digital twins in UAV navigation. A digital twin virtual environment is established using Unity3D, and the 3D A* algorithm is employed to plan optimal paths, thereby ensuring smooth and safe UAV operation and validating the UAV’s navigation and operational routes. A series of experiments and tests demonstrate that the system achieves high navigation efficiency and effectively avoids obstacles in complex environments. The system has broad applicability in fields such as security monitoring, logistics distribution, and facility management, providing robust technical support for UAV applications.