Clamping device used in tensile test

The invention discloses a clamping device used in tensile test, comprising a tensile core rod with external threads and an abutting conical surface, a pressing cap matched with the tensile core rod by threads, and a petal-shaped internal sleeve and a petal-shaped external sleeve that are contacted with the internal surface and the external surface of the test pipe material respectively; the internal conical surface of the petal-shaped internal sleeve is matched with the abutting conical surface of the tensile core rod; the petal-shaped external sleeve is externally provided with a rigid sleeve; and a fastening bolt is screwed down by a thread hole arranged in the rigid sleeve so as to contact with the petal-shaped external sleeve. The external surface of the petal-shaped internal sleeve is provided with toothed or corrugated or hooked or granular bulges. The clamping device has the active effects of having compact structure, being operated simply and conveniently, being applicable to the pipe materials of various diameters and wall thickness, and meeting the requirements of the axial tensile test of the pipe material which needs to be loaded by a higher axial load.