A method for analyzing energy consistency to process data, for use with an electronic apparatus, includes the steps of analyzing energy consistency to process data, performing a data-buffering process for outputting a data frame, performing a data-processing process for outputting a shaping residual after inputting the data frame, performing an energy-framing process for dividing the shaping residual into N sub-blocks after inputting the shaping residual to calculate energy of N sub-blocks to get a plurality of energy coefficients, performing a consistency-checking process for inputting the energy coefficients to check whether the energy coefficients can fulfill a threshold screening for consistency, enerating the decision about the data frame which should be processed by the long-type window coding if the spectral characteristics are consistent wherein the energy coefficients conform to the consistent energy relationship, and generating the decision about the data frame should be processed by the short-type window coding if the spectral characteristics are inconsistent wherein the energy coefficients can not conform to the consistent energy relationship.