The invention discloses a data processing method and a data processing device for predicting current. The method comprises the following steps of determining a plurality of target loads; predicting current waveforms of the plurality of target loads working in an electric power system according to a preset algorithm. According to the data processing method and the data processing system disclosed by the invention, the problem of whether the electric power system needs over-current protection or not is judged by a method of predicting a current effective value is easy to mistake in the related art is solved.