Abstract: The present disclosure relates to a method for monitoring and alarming hydrogen leakage of a fuel-cell vehicle and a system thereof. The method comprises the steps of: acquiring the current hydrogen concentration of a fuel-cell vehicle; judging whether the current hydrogen concentration is 0, if not, acquiring the measured hydrogen concentration, the hydrogen pressure drop value and the normal pressure range generated when the current hydrogen concentration of the fuel-cell vehicle is 0; judging whether the hydrogen pressure drop value exceeds the normal pressure range, if so, determining the predicted hydrogen concentration according to the measured hydrogen concentration and the hydrogen pressure drop value; judging whether the predicted hydrogen concentration exceeds the hydrogen leakage alarm threshold, and if not, determining the hydrogen leakage and issuing an alarm.