The invention discloses a bionic three-degree-of-freedom exoskeleton ankle joint. The bionic three-degree-of-freedom exoskeleton ankle joint comprises a mechanism rod piece and an ankle joint supportof a U-shaped structure. Two parallel shank force-bearing rods are hinged between the opening end of the mechanism rod piece and the opening end of the ankle joint support, so that the mechanism rod piece, the ankle joint support and the two shank force-bearing rods form a parallelogram structure restrained in the same plane to move when making shearing movement. An ankle joint bandage is arrangedat the opening end of the ankle joint support. A rotatable shoe pad is arranged at the upper side of the bottom of the ankle joint support. A drive element is hinged between the ankle joint support and one of the shank force-bearing rods. The center line L1 of the parallelogram structure, the rotating center line L2 of the shoe pad and the connecting line L3 of the centers of the hinged points ofthe ankle joint support and the two shank force-bearing rods are intersected at an ankle joint center point O of the opening end of the ankle joint support. The bionic three-degree-of-freedom exoskeleton ankle joint is higher in wearing comfort level and capable of being more coordinated with human motions, and the human body mobility can be truly enhanced.