The invention discloses an alarm device for preventing fatigue driving of a motor vehicle. The alarm device for preventing the fatigue driving of the motor vehicle comprises a single chip microcomputer, and an input interface and an output interface of the single chip microcomputer, and is characterized in that the input interface is connected with a fingerprint recognition device, a face and eyes positioning device, a heart rate monitoring device, a skin surface resistance monitoring device and an alcohol detection device respectively; the output interface of the single chip microcomputer is connected with an alarm device, a vehicle control system, a vehicle-mounted terminal, a card reader and a recorder respectively; the fingerprint recognition device, the heart rate monitoring device, the skin surface resistance monitoring device and the alcohol detection device can be arranged in a key, a safety belt or a steering wheel of the vehicle. The alarm device for preventing the fatigue driving of the motor vehicle has the advantages that the heart rate monitoring device and the skin surface resistance monitoring device can monitor the current state of a driver in real time, timely remind a system whether the driver is going to enter a sleepy period and ensure to give out a system prompt or start the alarm device in first time so as to reduce traffic accidents.