Provided is a method of locating a damage source of a wind turbine blade for tracking a damage source location of a blade used in a wind power generator, and more particularly, a method of locating a damage source of a wind turbine blade and an apparatus thereof in a large composite material structure capable of accurately locating a damage source even in a large composite material structure by detecting defects using contour maps written based on elastic wave energy value. The method of locating a damage source of the wind turbine blade according to the present invention can accurately locate the damage source even in the large composite material structure using at least two materials unlike the related art and can use a smaller number of AE sensor than the related art.