Abstract: To thoroughly analyze the impact of wingtip connection on the aerodynamic characteristics of formation drones, this study establishes a high-fidelity numerical simulation method based on polyhedral meshes. The accuracy of the computational approach was validated using a three-dimensional low-Reynolds-number FX63-137 straight wing case. Within the Reynolds number range of 1.5×10⁵ to 2.0×10⁵, a combined strategy of theoretical analysis and numerical simulation was employed to systematically investigate variations in the lift coefficient, drag coefficient, and lift-to-drag ratio of both the formation as a whole and its individual units. Based on the findings, a predictive model was developed to characterize how the aerodynamic performance of the formation varies with the number of units. The results indicate that wingtip connection can significantly enhance the maximum lift-to-drag ratio of formation drones. For instance, a two-unit formation achieves an improvement of approximately 30% compared to a single unit. This enhancement is attributed to a notable increase in the aspect ratio of the formation, leading to a lift distribution closer to the ideal pattern. Additionally, wingtip connection eliminates tip vortex interference from central units and reduces induced drag. However, as the number of units increases, this beneficial effect gradually diminishes. For example, when the number of units increases from 9 to 10, the improvement in the maximum lift-to-drag ratio at the same angle of attack decreases to about 2%. This attenuation occurs because the incremental aerodynamic benefit from adding more units becomes limited and is increasingly diluted relative to the growing reference area of the formation. Further validation confirms that the proposed predictive model demonstrates high accuracy and applicability in estimating the aerodynamic characteristics of formation drones across various configurations, with errors in both lift and drag coefficients remaining within 2%.