The present invention discloses a transformer substation energy efficiency assessment method based on an AHP (analytic hierarchy process). The method comprises: acquiring n index values for m to-be-assessed transformer substations; establishing an original index data matrix based on a gray relational analysis method, and carrying out standardized processing to generate a to-be-assessed index data matrix; establishing an index hierarchical structure, determining a relative weight,relative to a top level index, of each energy efficiency assessment index of a bottom layer of the index hierarchical structure to acquire a relative weight matrix; as for the to-be-assessed index data matrix, separately calculating an index value of each energy efficiency assessment index of each to-be-assessed transformer substation after the standardized processing, and a correlation coefficient between reference values of corresponding energy efficiency indexes in a reference line, thereby acquiring a correlation coefficient matrix; and calculating an integrated assessment result matrix of m to-be-assessed transformer substations. According to the method disclosed by the present invention, a reasonable degree of energy efficiency of the transformer substations can be analyzed, a power saving magnitude before and after reconstruction of the transformer substations can also be analyzed and assessed, so that the method has the advantages of high data assessment accuracy, and high-speed and efficient assessment.