The magnetic field sensor

The utility model discloses a magnetic field sensor, which includes a signal input and detection unit, a display and a data processing unit separately connected with the signal input and detection unit and the display. The signal input and detection unit includes a detection controller with a multi-pin port, a magnetic field converter, a signal conditioning circuit and a multi-core terminal. The data processing unit includes a data processing controller, an analogue photocoupler, a memory, an I[2]C bus and a USB port separately connected with the data processing controller and two power supply modules for the sensor. The detection controller is used to carry out detection of hot swap of the sensor, identification of the sensor, self-test of the sensor and data communication and command interchange with the data processing controller. The detection controller is also used to control online detection and online debugging of the sensor.