Axial excitation device and method for pipeline nondestructive testing

The invention relates to an axial excitation device and method for pipeline nondestructive testing, and belongs to the technical field of pipeline detection. The device comprises a slip arranged on a pipeline in a sleeving mode, the slip is fixedly connected with the pipeline, a movable ring and a positioning ring are sequentially arranged on one side of the slip on the pipeline in a sleeving mode, and the positioning ring is fixed; the movable ring and the positioning ring are connected through N telescopic pieces, N is an integer, one end of each telescopic piece in the length direction is connected with the positioning ring, the other end of each telescopic piece is connected with the movable ring, the N telescopic pieces control telescopic movement through a same driving piece, the driving piece can control the N telescopic pieces to stretch at the same time to drive the movable ring to collide with the slip after being stressed, and then the collision is converted into the axial excitation of the pipelin