Pipeline welding seam nondestructive testing method and system

The invention provides a pipeline welding seam nondestructive testing method and system, and belongs to the technical field of pipeline detection. The method comprises the following steps: controlling a generator arranged on a to-be-detected pipeline to emit Rayleigh waves, and controlling a piezoelectric transducer arranged on the to-be-detected pipeline to carry out echo signal detection to obtain an echo signal with a time domain difference; reconstructing and generating echo image data and enhanced image data based on the echo signal; inputting the echo image data and the enhanced image data into a pre-constructed CycleGAN model for sample expansion to obtain a sample set; inputting the sample set into a preset neural network model for training to obtain a defect detection model; and acquiring a to-be-detected signal of the to-be-detected pipeline, and inputting the to-be-detected signal into the defect detection model to obtain a defect detection result. Therefore, the problem of large neural network alg