To mitigate tether entanglement in regional coverage missions involving tethered UAVs in complex environments, we propose a spanning-tree–guided method that couples spatial partitioning with topological constraint enforcement. The algorithm decomposes the largest connected free space into multiple subregions, constructs a spanning tree rooted at boundary points in each, and generates Hamiltonian paths on a refined grid constrained by the tree topology. Experiments on \(100 \times 100\) grid maps with 4–10 UAVs and a 5% obstacle density confirm that the method consistently yields complete, non-overlapping coverage within an average planning time of 2.1 s. Compared to classical approaches such as Boustrophedon, STC, and MSTC*, the proposed strategy demonstrates superior path continuity, enhanced multi-agent coordination, and robust tether safety—highlighting its suitability for real-world deployment.