This paper proposes a Voronoi diagram-based cooperative encirclement guidance method for fixed-wing aircraft to encircle fast-moving ground vehicles. In a limited area, the Voronoi partitions of multiple fixed-wing aircraft continuously surround and reduce the area of the vehicle’s Voronoi region, achieving multi-directional encirclement of the vehicle target. The aircraft cluster determines dynamic encirclement tracking points based on the relative motion relationship with the target, flies toward these points using the L1 navigation tracking method, and designs outer-loop guidance commands for multiple aircraft using a consensus protocol. Numerical simulations verify the effectiveness of the proposed method.