The invention discloses an inside processing device for a pipeline. The processing device comprises a flexible transmission shaft, a support and a driving device; the flexible transmission shaft comprises a first end and a second end which are opposite to each other; the support is circular; the axis of the support is connected with the first end; a plurality of rollers making contact with the inner wall of the pipeline are arranged on the periphery of the support at intervals; and the driving device is connected with the second end and can transfer the twisting force to the support through the flexible transmission shaft so as to drive the support to move in the length direction of the pipeline. With the processing device, work such as cleaning, dredging, grinding and the like can be performed on the inner wall of the pipeline, to-be-transported objects can also be placed in front of the movement direction of the support and can be transported to the target position through the support, and the movement of the support in the pipeline is not affected by the shape of the pipeline. The processing device is applied to inside processing of the pipeline, the pipeline is not required to be dismounted or cut, and a lot of manpower, material resources and time can be saved.