The random interference of the external environment and the imperfection of the thermal imaging system bring various noises to the thermal infrared image. Noise will blur the image, destroy image features, reduce human visual understanding and analysis ability, and seriously affect the performance of digital processing such as image segmentation, image compression and image recognition. The purpose of image denoising is to filter out the mixed noise signal as much as possible while retaining the useful signal, so as to improve the visual quality and facilitate subsequent processing.