Fire-fighting telephone bus communication circuit

The utility model relates to a fire-fighting telephone bus communication circuit, which comprises a bus controller, a power supply circuit, a code sending circuit and a code receiving circuit, the power supply circuit is connected with the code sending circuit; the code sending circuit and the code receiving circuit are respectively connected with the bus controller; the code receiving circuit comprises a first shaping circuit, a level conversion circuit and a second shaping circuit; the level conversion circuit is respectively connected with the first shaping circuit and the second shaping circuit; the first shaping circuit is used for shaping a continuous square wave with a certain frequency and amplitude on a bus into a low-level pulse signal with a corresponding width; a level conversion function is realized through a level conversion circuit, and a level signal suitable for being identified by a bus controller is generated; and the signal is further shaped through the second shaping circuit, so that dete