Large bottle type vessel and long tube trailer steel cylinder internal detection method and system

The invention belongs to the technical field of special pressure vessel internal detection, and discloses a large bottle type vessel and long tube trailer steel cylinder internal detection method and system, the large bottle type vessel and long tube trailer steel cylinder internal detection system is provided with an extension shaft used for providing a support effect for a detection propulsion module and a rotation module; a detection propelling module used for driving the detection module in the steel cylinder to adjust the position back and forth through a propelling rotating structure; a rotating module used for clamping or loosening the long shaft through rotation of a motor; and a steel cylinder internal detection module used for detecting defects on the inner wall of the steel cylinder. The steel cylinder inner detection module is placed on the inner side of a steel cylinder and connected with the lengthened shaft through the long shaft, the detection propelling module and the rotating module are inst