The invention discloses a wedged drainage strain clamp, and aims at providing a wedged drainage strain clamp which can effectively reduce the maintenance procedure, reduce the maintenance cost, is good in structure stability, has a self-wedging function and can effectively solve the problems of resistance increasing and heating caused by looseness of the drainage strain clamp. The wedged drainage strain clamp comprises a clamp body and a wedged drainage body, wherein the clamp body is connected with a lead; the wedged drainage body comprises an upper drainage post, a lower drainage post and a wedged drainage body connection structure; the upper part of the upper drainage post is fixedly connected with the clamp body; the lower part of the upper drainage post is connected with the upper part of the lower drainage post through the wedged drainage body connection structure; the lower part of the lower drainage post is connected with a jumper wire; the wedged drainage body connection structure comprises a taper sleeve and a wedging cone; openings are formed in the upper end and the lower end of the taper sleeve; the wedging cone is inserted into the taper sleeve; the lower end of the upper drainage post is connected with the outer side surface of the taper sleeve; and the upper end of the lower drainage post is connected with the lower end of the wedging cone.