The work aims to explore the effect of fragment impact distance on the penetration behavior and fragment residual velocity to provide theoretical basis for the optimal design of protective materials under the condition of multi-fragment impact. By the finite element simulation method, based on the penetration behavior of a single fragment, the penetration performance of different shapes of fragments was studied, and the effect of the spacing on the penetration resistance and the penetration behavior of the target was analyzed with the example of two fragments impacting the target at the same distance of 10 mm. The mechanical responses of the fragments with different shapes were significantly different when they impacted the target at a distance of 10 mm, and the penetrating ability of the cylindrical fragment was the strongest. When the distance between the two fragments was less than 0.5-1 times the bullet diameter, the superposition effect of stress waves was enhanced, which led to the local damage of the target plate and the formation of a concentrated damage area. The variation of residual velocity when two fragments penetrate the target at a close distance at the same time is the result of the deformation of the target plate, the superposition of stress waves and the coupling effect of fluid dynamics. This study can provide theoretical support for the evaluation of fragment penetration performance and the optimal design of the protective structure.