A bidirectional energy storage device for a joint includes: a sleeve comprising an open end and an opposite, closed end; an elastic member attached to the sleeve; a sliding member slidably arranged at the open end of the sleeve, wherein opposite ends of the elastic member are respectively in contact with the closed end of the sleeve and the sliding member; a first telescopic link comprising a first end pivotally connected to the sliding member and an opposite, second end; and a second telescopic link comprising a first end pivotally connected to the sliding member and a second end. The second ends of the first telescopic link and the second telescopic link are pivotally connected to a rotating member at an end of the joint, and the first telescopic link and the second telescopic link are to extend and retract to drive the sliding member to side along the sleeve.