Corner reflectors have strong reflection echo characteristics for radar electromagnetic waves,and can simulate military targets such as ships and armored vehicles. The surface of the metal corner reflector gets damaged due to rust,oil pollution and other reasons during the operation process,resulting in a serious decline in its performance. The Radar Cross Section(RCS)characteristics of the corner reflector with different damage areas and damage numbers are respectively studied. The RCS value of the metal corner reflector decreases rapidly with the increase of damage number and areas,which can effectively and quantitatively evaluate the electromagnetic wave reflection capability of the corner reflector.