In order to detect the inner surface defects of the pressurized conveying pipeline of rocket and improve the quality of the pipeline,investigation on the application of endoscope technology in the inner surface of the rocket pipeline was carried out.In this paper,the technical characteristics of the endoscope equipment and the selection of the equipment probe and the technological methods of the size measurement and to calibrate the dimension of defects are introduced.The types of the detected inner surface defects were classified and summarized.Electron microscope and the metallographic techniques were used to analysis defects that are difficult to be identified.The results show that when video endoscope inspection technology was used to inspect the inner surface of the rocket pipeline,the probe with a larger diameter should be preferentially selected according to the inner diameter size of the pressurized pipeline.By using the defect comparison method of the measurement calibration,the results are more accurate with strong on-site detection applicability.The image of the defect by endoscope display technology is clear and stable,and the types of the defect in the inner surface can be correctly identified.Finally,the effect of the detection can meet the processing requirements.