Method for identifying internal and external defects in magnetic flux leakage internal detection of oil and gas pipeline

The invention discloses a method for identifying internal and external defects in magnetic flux leakage internal detection of an oil and gas pipeline and belongs to the technical field of oil and gaspipeline detection. The method includes a magnetic flux leakage internal detection system and a weak magnetic detection system, wherein the weak magnetic detection system transmits a collected weak magnetic signal to a data analysis system through a weak magnetic detection sensor, moreover, the magnetic flux leakage internal detection system transmits a collected magnetic flux leakage signal to the data analysis system through a magnetic flux leakage internal detection probe, if defect signals are detected at the same position at the same time, an internal defect can be determined, if only themagnetic flux leakage signal is detected to have the defect, and the weak magnetic signal has no defect, an external defect is determined. The method is advantaged in that whether the defect distributed on the pipeline is the