The invention discloses an alarm device. The alarm device comprises a fingerprint identifier, a loudspeaker, a switch, a setting button, a Bluetooth-containing single-chip microcomputer, a vibration sensor, a charging socket, an electric quantity display screen, a battery, a flashing light and a voltameter. The fingerprint recognizer, the loudspeaker, the switch, the setting button, the vibrationsensor, the electric quantity display screen, the battery, the flashing light and the voltameter are respectively connected to the Bluetooth-containing single chip microcomputer. The fingerprint identifier, the loudspeaker, the switch, the setting button, the vibration sensor, the electric quantity display screen, the flashing light and the voltameter are respectively connected to the battery. Thebattery is connected to the charging socket. The alarm device is small in size, convenient to carry, high in alarm sensitivity and powerful in anti-theft function. A user can know the electric quantity at any time through the external electric quantity display screen, so that use is convenient and safe.The safety of valuables such as personal computers is effectively guaranteed, and great convenience is brought to daily life of students.