Stepping inspection device for inner wall of pipeline

The utility model discloses a pipeline inner wall stepping type inspection device, which comprises a first centering mechanism, a measuring mechanism, an advancing mechanism and a second centering mechanism which are sequentially connected to form a combined body, the first centering mechanism and the second centering mechanism have the same structure, are symmetrically arranged and are respectively positioned at the head part and the tail part of the combined body, and the advancing mechanism is positioned at the tail part of the combined body before the measuring mechanism axially moves. And a plurality of centering arm combinations of the two centering mechanisms extend alternately and are respectively pressed on the corresponding positions of the inner wall of the pipeline. The other end of the advancing mechanism is connected with one end of the second centering mechanism. The device is convenient and labor-saving to operate, does not damage the inner wall of the pipeline, reduces the cost of manpower an