Alarm detecting method and computer device thereof

An alarm detecting method applied on a computer device is disclosed in the present invention. The method includes utilizing a G-sensor of the computer device to detect a variation of gravity acceleration, transmitting an actuating signal to a controller by the G-sensor according to the variation of the gravity acceleration, the controller reading the actuating signal and determining whether the variation of the gravity acceleration is substantially greater than a predetermined threshold value, the controller outputting a controlling signal to an audio codec when the variation of the gravity acceleration is substantially greater than the predetermined threshold value, and a speaker generating an alarm audio by the audio codec according to the controlling signal. The controller drives the speaker to generate the alarm audio when an operating system of the computer device has not started.