Abstract: The present invention relates generally to a method for preventing gravity-induced loss of consciousness (G-LOC), which arises from increased acceleration during flight, and more particularly, to a G-LOC warning method and system using a G-LOC warning algorithm, which detects, in advance, risk factors that cause a G-LOC state by monitoring a change in the electromyogram (EMG) signal in real time. According to the G-LOC warning method and system using the G-LOC warning algorithm of the present invention, because information about the EMG signal is measured and collected in real time, changes in the EMG signal of a pilot who is exposed to high levels of acceleration during a flight maneuver are measured and checked on the spot.