Compared with magnetic flux leakage testing method, electroelectroultrasonic testing technology has the advantages of direct customized measurement of corrosion defects and high detection accuracy. However, it is only suitable for the detection of liquid pipelines because the operation requires the use of liquid coupled media. In the 1970s, the pipeline piezoelectric ultrasonic corrosion internal detector developed abroad in the detection accuracy, positioning accuracy, data processing. The passing capacity of the equipment has reached a high level, which can meet the actual detection requirements.