This article has experimentally and numerically investigated the high‐velocity impact resistance of the composite sandwich panel with an M‐shaped lattice core reinforced by nano‐SiO2. For this purpose, firstly, a glass fiber resin epoxy sandwich panel has been fabricated in the laboratory. In this regard, the vacuum‐assisted resin transfer molding (VARTM) method has been used to achieve a laminate without any fault. In order to improve the impact resistance of the composite, the nano‐SiO2 were added to the resin epoxy matrix as filler with the ratios of 1%, 2%, and 3% of the composite's total weight. A scanning electron microscope (SEM) has been utilized to observe the microscopic structure of the composites, and it shows an exceptional homogeneous mixture of nano‐SiO2 particles in the resin epoxy matrix. From the experiment results, it was figured out that by adding 1 to 3 wt% of nano‐SiO2 into the composite, the output velocity of the projectile decreases. On the other hand, the results showed that when the projectile collides with the core of the sandwich panel, it remains in the sandwich panel and its output velocity will be zero. However, when the projectile does not completely collide with the core, the output velocity of the projectile will not be zero. In order to validate the results, a finite element analysis (FEA) has been developed to simulate the high‐velocity impact test. Then the experimental data has been compared to numerical simulation and good agreement was observed.