The invention provides a modeling method of electric energy quality interference source characteristic harmonic wave. The modeling method comprises the following steps: collecting modeling data to obtain an initial data set; preprocessing the initial data set, and carrying out working condition identification; and according to a working condition and the modeling data, establishing an electric energy quality interference source characteristic harmonic wave model. The method provided by the invention overcomes the defects of low efficiency, large calculated quantity and the like since machine learning, a neural network algorithm and a mathematical analysis method are depended to realize model creation in the prior art. The modeling method of the electric energy quality interference source characteristic harmonic wave on the basis of a law of large numbers has the advantages of being simple, easy in learning, practical, efficient and small in calculated quantity and is especially suitable for analyzing and processing a large-scale data set so as to guarantee the safety and the electric energy quality of a power supply system.