Abstract: The internal and external surface cracks of the base material of the pressure-bearing equipment in use are a kind of more harmful defect. For this type of defect, magnetic powder, penetration, eddy current, radiation, and conventional ultrasonic detection are usually used. Conventional inspection technology is relatively mature, but it also has certain limitations. In this paper, high-frequency guided wave technology is used to test and research the internal and external surface simulate cracks of pressure-bearing equipment, and a 1 300 mm×520 mm crack test plate is designed and processed. The results show that the high-frequency guided wave detection technology has high feasibility in the internal and external surface cracks of the base metal of the pressure equipment, with high sensitivity, large detection range and high detection efficiency; when the detection distance is 600 mm, the depth of 0.5 mm can be found; For cracks with a depth of 1 mm, the maximum distance that can be detected is 593 mm; for cracks with a depth of 5 mm, the maximum distance that can be detected is 1 023 mm.