With the development of science and technology, the development of non-destructive testing is more and more mature, and Ground penetrating radar (GPR) has been widely used because of its advantages of fast detection speed, continuous detection process, high resolution, convenient and flexible operation, and low detection cost. However, it is rarely used in the detection of bellows defects. Therefore, the validity and applicability of GPR needs to be verified for detecting grouting defects of bellows in box girders. The box girder slab is simulated by placing bellows in the reinforced concrete slab. Ground penetrating radar (GPR) profiling method is used to detect grouting defects of bellows in reinforced concrete slabs. The two-dimensional and three-dimensional images of ground penetrating radar detection results are analysed. The results show that: Combining the X and Y direction detection images of ground penetrating radar, the specific location of the cavity defects in the bellows can be known. The three-dimensional slice of ground penetrating radar can roughly reflect the size of the internal cavity defect in the bellows. The two-dimensional and three-dimensional images of ground penetrating radar (GPR) can verify each other and complement each other when detecting the internal void defects of reinforced concrete plate corrugated pipe, which is helpful to grasp the internal defects of corrugated pipe in depth. The experiment proves that the ground penetrating radar is effective and promising for the detection of reinforced concrete plate bellows, and can be used for the detection of box girders in bridge engineering.