Low water level detector

The utility model relates to a low water level detector which comprises a shell. A water inlet is arranged at the bottom end of the shell, the shell further comprises a bushing, a magnetic-sensitive Hall device, a permanent magnet and a control circuit, wherein the magnetic-sensitive Hall device is arranged in the bushing, the permanent magnet is sleeved on the outer wall of the bushing, and the control circuit is connected with an electric signal output end of the magnetic-sensitive Hall device. The magnetic field nearby the magnetic-sensitive Hall device is changed by vertical movement of the permanent magnet, the magnetic-sensitive Hall device can detect the changed magnetic field and transform the changed magnetic field into electric signals to be outputted to the control circuit, and the control circuit transforms the electric signals into digital display signals and outputs the digital display signals. The low water level detector is simple in structure, can automatically display water level difference