This study conducted experimental research on the scale effect of the impact resistance capability of reinforced concrete structures with high matrix material strength and high reinforcement ratio. The study was designed for typical nuclear power plant structures, and experiments were carried out on target plates with 4 sets of 1/5 scale and 1 set of 2/3 scale at an impact speed of around 300 m/s. The results indicate that the dimensionless penetration depth of the 2/3 scale target plate matches well with the fitting curve of the dimensionless penetration depth of the 1/5 scale target plate, with an error not exceeding 4%, and the depth of the projectile penetrating the target plate did not show a significant scale effect. In conjunction with existing research results, it is analyzed that the difference in strength between the concrete coarse aggregate and the overall target plate is the main cause of the scale effect. The higher the concrete strength and the reinforcement ratio, the less obvious the scale effect. The study results show that in future research on the impact resistance performance of reinforced concrete structures with high reinforcement ratio (volume reinforcement ratio above 3%) and high strength (above 60 MPa) at speeds below 300 m/s, the results from small-scale experiments can reflect the impact resistance performance of the prototype structure. The conclusions of this study can provide important data support for the impact resistance performance experiment research of nuclear power plant structures.