A holder device which comprises a first tube body and a second tube body pivotally connected to each other； a first rod pivotally connected to the second tube body, a second rod pivotally connected to the first tube body； a first claw arm and a second claw arm respectively provided with a first holding part and a second holding part and a first connecting part abd a second connecting part, all of which pivotally connected to the second tube body； a third rod and a fourth rod pivotally connected to the first connecting part and the second connecting part, respectively； a screw nut pivotally connected to the third rod and the fourth rod； a screw rod connected to the screw nut, wherein the screw rod is driven by a drive rod via a first universal joint, a fifth rod, and a second universal joint. As a result, the screw nut is driven to move by the drive rod and the movement of the first, second holding part is controlled via the third, the fourth rod and the first, the second connecting parts, thereby stably maintaining the holding force. In addition, the second rod and the first rod are controlled to control the second tube body and the first, the second holding parts to swing with respect to the first tube body.一種夾持器具，包含彼此樞接的第一、二管體。第一桿，樞接第二管體。第二桿，樞接第一桿。第一、二爪臂，分別具有第一、二夾持部和第一、二連接部，皆樞接第二管體。第三、四桿，分別樞接第一、二連接部。螺帽，樞接第三、四桿。螺桿，螺接螺帽。螺桿經由第一萬向接頭、第五桿、第二萬向接頭受驅動桿驅動。藉此，經由驅動桿帶動螺帽移動並透過第三、四桿以及第一、二連接部，則控制第一、二夾持部移動，而能夠穩定地維持夾持力量。此外，控制第二桿、第一桿來控制第二管體及第一、第二夾持部相對於第一管體的擺動。
