Abstract: In view of the burst failure of an interpolated HDPE repairing oil-gathering pipeline during the line sweeping and suppressing operation, the reasons for the failure of the pipe were systematically studied by macro analysis, physical and chemical performance testing, scanning electron microscope(SEM), energy dispersive spectrometer(EDS) and X-ray diffraction(XRD). The results show that the chemical composition, metallographic structure, yield strength and tensile strength of the pipe meet the standard requirements, but due to service aging, the plasticity is significantly lower than that of the standard material. In spite of the internal HDPE repair, the internal and external corrosion of the pipeline cause the pipe wall to be significantly thinned, and the pressure limit is only 5.3 MPa, then the downstream blockage leads to burst failure during the line sweeping and pressure process.