Abstract: It is high detection precision,convenient and flexible,high efficiency of ground penetrating radar;and according to the type of diseases,the depth of the burial and the detection precision,the different types of antenna combination can be selected to achieve the best detection effect.The method does not cause any damage to the detection target in the detection process,and the result is intuitive.It is the most suitable method to detect the diseases of the ancient wall at present.In this paper,100 MHz,270 MHz,400 MHz,900 MHz and 1600 MHz antennas are used to test the top and side surfaces of the ancient wall,and the locations,scopes,depths and scales of the diseaes are explored in an all-round way.According to the ground penetrating radar atlas of different central frequency antennas,the effectiveness,advantages and disadvantages,and application scope of different frequency antennas are compared and analyzed in detecting the ancient wall diseases.