The invention provides a three-way connecting pipe and a Y type automatic tracking fire extinguishing water monitor based on the three-way connecting pipe. The three-way connecting pipe comprises a main body module connected with a water supply pipeline, a monitor head connecting pipe in pipe connection with the main body module, a vertical rotating module and a horizontal rotating module for realizing three-dimensional rotation, and a driving module; the driving module and the vertical rotating module are detachably and fixedly connected to the main body module; the horizontal rotating modulesleeves the main body module; one end of the monitor head connecting pipe is connected to the vertical rotating module; a monitor head module is mounted at the other end of the monitor head connecting pipe; and the vertical rotating module comprises the main part of the three-way connecting pipe for achieving a vertical rotating function. A monitor body is of a Y type structure; and through multiple times of flow separation, the turbulence of water currents in the pipe is improved, and the flowing speed loss is reduced. A monitor head transmission turbine structure is placed in the middle position of the whole monitor body; and the overall structure stress is more reasonable.