Abstract: Humming notation is an important method and process of composing music. Considering the complexity of humming audio and the influence of various environmental factors, this paper analyzes the basic characteristics of humming audio. On the basis of windowed Fourier Transform, the humming audio is regionally divided, defined and extracted according to the notes. A method of fast extraction of fundamental frequency is proposed based on relative amplitude of humming audio. And further a variable-region Fourier Transform iteration algorithm is designed and implemented programmatically by Python 3.6. This iteration algorithm can recognize humming melody more accurately, obtain the pitch and length of each note of humming, and automatically form a digital music score. The accuracy of the experimental test reached 84.3%. The achieved results show that the algorithm can identify humming tunes more accurately, thus it would be a feasible recognition and notation algorithm for developing composing-assisting software with good application prospects.