Automatic water rescue bracelet

The invention relates to an automatic water rescue bracelet, and belongs to the field of electronic apparatus. A heart rate monitoring device measures pulse by photoelectric plethysmography, and obtains accurate pulse data; then a photoelectric sensor converts a measured signal into an optical signal, and then the optical signal is converted into an electrical signal by means of a photoelectric element; a comparator compares a mean value of the pulse data with a proposed standard value, and determines whether the pulse data are within a safe range or not; then a water conductive device switchis used for judging whether a person falls into water, thereby forming a second judgment basis; and then, an A/D (analog-digital) converter converts an analog signal into a digital signal, and transmits the digital signal to an MCU (microprogrammed control unit) for processing, the MCU processes the digital signal transmitted from the A/D converter, and if measured pulse frequency is within a dangerous frequency range, th