In order to effectively suppress background noise in the complex environment of the factory and obtain the useful information contained in the audio signal, an audio noise reduction method based on the combination of multi-window spectral subtraction and least mean square filtering algorithm is proposed. First use the improved multi-window spectrum subtraction, the gain factor in the modification of the spectrum reduction relationship is used to suppress the noise-free frequency, effectively avoid the production of music noise and increase the audio perception of non-smooth noise interference. Then use the changeable step-by-side adaptive LMS filtering algorithm based on the double-type normal cleaning function to adjust the step-up audio signal that has initially denoising the audio signal, thereby achieving the purpose of eliminating the noise component in the audio. The simulation experiment results show that this method is less than about 7dB of the signal-to-noise ratio of 7dB compared to the traditional multi-window spectrum reduction, and the fixed step LMS algorithm is increased by 3 to 4 dB, and the LMS algorithm of the traditional multi-window calibration step is increased by 1 to 2dB, and this method is simple and easy to have a good practical application value.