The invention discloses a clamping mechanism of a power transmission tower climbing robot and a climbing robot. A problem that climbing in the prior art is mainly targeted for tubular structures is solved; and the clamping mechanism of the power transmission tower climbing robot has the beneficial effects that the structure is compact, the flexible degree is high, the clamping mechanism of the power transmission tower climbing robot can adapt to the changing of an angle of angle iron in a power transmission tower and a clamping claw is kept parallel to the angle iron surface. The technical scheme is that the clamping mechanism of the power transmission tower climbing robot comprises manipulators used for clamping the tower and a mounting plate, wherein the manipulators comprise clamping claws; the clamping claws can be opened or closed to clamp one side of a tower; the manipulators can advance or retreat relative to the side part of the tower; the mounting plate is supported by a basebottom plate; the mounting plate is arranged at the end parts of the manipulators; the manipulators realize swinging motion through mechanical arm pitching supporting mechanisms; the manipulators swing with vertical central axes of the two manipulators as central lines to adjust angles of the manipulators relative to the mounting plate so as to realize centering clamping of the clamping claws to the angle iron of the tower.