In order to fix a Power tower climbing robot on a tower reliably, a novel double -V-clamper is proposed in the paper. The gripping claw has an angle fixed V-groove and a variable length, so that it is possible to clamp angle bars with various specifications in different directions. The CAD and mathematical model of the clamping mechanism were suggested and the clamping force was simulated. Furthermore，Prototype experiments were made in laboratory. The results show that the gripper can grasp angle bars firmly and reliably which widths vary from 80 to 220 mm in several directions, for the three-dimensional movement of the power tower climbing robots.
