The utility model provides a ground clamp including a static armature, a moving armature and a rotating rod. The moving armature hinges with the front end of a control arm through an armed lever hinged shaft. The rear end of the control arm hinges with the rear end of the static armature. The rotating rod threads on a support screw hole. The lower end face of the rotating rod has two working status of pressing and separating relatively to the force-bearing working face of the control arm. The force-bearing working face of the control arm is a concave arc face. Since the force-bearing working face of the control arm of the ground arm is a large concave arc face, no matter the lower end face of the rotating rod is in a perpendicular or an inclined state, the force-bearing working face of the control arm is a concave arc face can receive a pressing force of the lower end face of the rotating rod well and transmit to the moving armature through a retained face contact, thereby guaranteeing solid short circuit connection. Moreover, the rotating rod and the support are connected in a universally spherical manner. And the lower end face of the rotating rod is designed into a convex arc face. Thus, the operation convenience, the connection reliability and the like of the ground clamp are improved substantially.