The invention belongs to the technical field of pipeline welding, and particularly relates to a local blocking and argon filling device with a camera function and for a small-caliber pipeline weld junction. According to the local blocking and argon filling device with the camera function and for the small-caliber pipeline weld junction, a first wheel set and a first annular airbag are sequentiallyat one axial end of the circumferential surface of a central pipe from outside to inside in the axial direction of the central pipe as a set; a second wheel set and a second annular airbag are sequentially arranged at the other axial end of the circumferential surface of the central pipe from outside to inside in the axial direction of the central pipe as another set; the first annular airbag andthe second annular airbag can be inflated and deflated; and the central pipe can move in a pipeline in the axial direction of the pipeline through the first wheel set and the second wheel set. By adoption of the local blocking and argon filling device with the camera function and for the small-caliber pipeline weld junction, the interior of the pipeline can be prevented from being stained and damaged by other parts in the local blocking and argon filling device, and the local blocking and argon filling device is convenient to move and adjust. A camera is arranged at the front end of the central pipe so that a clear image of the surface of a weld joint in the weld junction can be obtained, and the requirements for visual observation and inspection are met.