Fractal theory, as a new research method, has been widely studied in various fields. Based on fractal theory and edge computing, the numerical simulation of ballistic limit of protective structure is deeply studied in this paper. In this paper, the ballistic limit of spherical aluminum projectiles colliding with Whipple protective structure under the condition of encounter velocity of 1~12 km/S is numerically simulated. By combining the existing experimental data with the data obtained by numerical simulation, the fitted impact limit equation is obtained by multiple linear regression, and the linear relationship of the fitted equation is tested for significance. According to the critical failure kinetic energy discrimination method proposed in this paper, the high-speed impact protection performance evaluation of the above two structures is given, and the experimental verification is carried out in the ballistic range. The experimental results are consistent with the theoretical predictions. It is proved that the ballistic limit of Whipple protective structure in high-speed region is significantly higher than that predicted by traditional ballistic limit equation, which has reference value for spacecraft protective structure design and spacecraft in-orbit safety analysis.