The utility model relates to a building communication special joint, including body and movable plate, the body is equipped with the spout, and the both sides symmetry of body is equipped with a plurality of rectangular channels, and the body upper end is installed and is connected the lid, connect to cover and install the hollow tube, install the gate valve on the hollow tube, the symmetry is equipped with a plurality of draw -in grooves on the movable plate, draw -in groove and rectangular channel are equipped with the through -hole on being in same straight line between the adjacent draw -in groove, the guide pulley is installed to the lower extreme of movable plate, the guide pulley is installed in the spout, and the upper end symmetry of movable plate is equipped with the fixed block, set screw is installed to the fixed block. The utility model discloses the setting has the movable plate of removal and fixed function, helps operating personnel to change arranging of body inner space size as required, helps placing the fixed plate through setting up the draw -in groove with the rectangular channel, and this helps the inside subregion of body, helps installing the fixed of threaded rod and movable plate through setting up the through -hole.