The invention relates to an ultra-short-term peak load prediction method and a system thereof. The ultra-short-term peak load prediction method includes the steps of acquiring meteorological prediction information; performing ultra-short-term load prediction on the basis of an established peak load prediction model and the acquired meteorological prediction information, wherein the peak load prediction model comprises a peak load index, meteorological factors influencing the peak load and the correlation of all meteorological factors; and the peak load prediction model is based on the peak load and the meteorological factors influencing the peak load. An actual calculation result provided by the invention proves that the method is effective in peak prediction, and the prediction precisionof an ultra-short-term load is improved.