Disclosed herein are a drowsy-driving prevention method and a drowsy-driving prevention system that execute artificial intelligence (AI) algorithms and/or machine learning algorithms in a 5G environment connected for Internet of Things in order to control a stimulation unit and a measurement unit. The drowsy-driving prevention method may include a stimulating step, a measuring step, and a determining step. A stimulation unit outputs a stimulus in order to stimulate a sensory organ of a driver, and then a measurement unit measures a biometric signal of the driver from the time when the stimulus is outputted. Upon determining that the biometric signal of the driver is not a response to the stimulus, the stimulation unit may output the stimulus again.