An extendable cable distribution device in accordance with an embodiment of the present disclosure can include a main block for receiving the end portion of a composite cable supplied from the outside, and providing the passage through which the received composite cable is distributed; at least one sub-block located to be detachable at one side of the main block, and for guiding the distribution direction of a part of the composite cable distributed while passing through the main block; and a connector located on the outer circumferential surface of the at least one sub-block, and electrically connected with at least part of the distributed cable. According to an embodiment of the present disclosure, it is possible to provide the cable distribution device capable of distributing the supplied composite cable and rotating the distributed cable depending upon the direction extended to the outside. In addition, according to an embodiment of the present disclosure, when the distributed cable is added, it is possible to simply extend the cable by the number or in the direction desired by an installer by additionally mounting the modular sub-block.