The rapid and accurate localization of impact points of supersonic projectiles on a target surface is a crucial factor influencing the performance of intelligent target-reporting systems. When obtaining projectile impact points by establishing an impact model, the sensor layout plays a vital role in determining the accuracy of the projectile impacts. In addressing the selection of the optimal sensor-layout method, this study proposes a projectile-impact-accuracy analysis method that combines a geometric dilution of precision analysis with optimization algorithms. This is achieved by calculating the area of iso-lines representing high-precision projectile impact points and searching for the optimal sensor layout within a specific range. The proposed method is validated through multiple sets of theoretical feasibility simulations, simulations with limited impact ranges under real conditions, and extended experiments. Results from these experiments reveal the fundamental principles governing sensor layouts for high-precision projectile impact localization. The effectiveness of the proposed projectile-localization accuracy analysis method is demonstrated by the successful selection of high-precision sensor layouts, with the identified optimal sensor layouts aligning with the fundamental principles of high-precision sensor deployment.