The invention provides a level transmitter. The transmitter comprises a magnetic float level meter, a sensor of the transmitter is arranged outside a main tube of the magnetic float level meter, the sensor is in the same magnetic coupling region of the magnetic float level meter, a dry reed pipe in the sensor conducts self-actuation by a magnetic field effect of a magnetic steel in the magnetic float level meter, and the dry reed pipe is connected to a signal conversion circuit. The transmitter makes a level meter signal of transmission more direct and precise, provides convenience for centralized display or automatic control of a computer, and achieves long-distance detection and control of a liquid level.