Small-diameter internal thread copper pipe clamping tool and using method

The invention relates to the technical field of tool clamps, in particular to a small-diameter internal-thread copper pipe clamping tool and a using method, and is characterized in that the small-diameter internal-thread copper pipe clamping tool comprises a tightening unit used for carrying out clamping type fixing on the outer wall of a copper pipe and an outer supporting unit used for carrying out outer supporting on the inner wall of the copper pipe to prevent deformation; the tightening unit comprises an elastic hoop piece, the elastic hoop piece is in a herringbone shape, one end, with one end, of the herringbone shape is connected with a first stretching plate, and the other ends, with the two ends, of the herringbone shape are connected with two second stretching plates respectively. By means of the mode that the copper pipe is fixed in a clasping mode through the elastic hoop pieces, the comprehensive contact type extrusion mode on the circumferential outer wall of the copper pipe can be achieved, th