The invention discloses a convolutional neural network self compression-based image denoising method and system. The image denoising method comprises the steps of inputting a to-be-denoised image to afirst neural network model; performing neural network implicit information extraction processing on the to-be-denoised image by adopting a convolutional layer in the first neural network model to obtain image contour information of the to-be-denoised image; performing dimension reduction sampling processing on the image contour information by adopting a dimension reduction sampling layer in the first neural network model, and finally outputting an underlying output image; inputting the underlying output image to a second neural network model; performing image up-sampling processing on the underlying output image in the second neural network model, performing interpolation processing by adopting most adjacent pixel points simultaneously in the image up-sampling processing process, and outputting a restored denoised image; and taking the finally output restored denoised image as a denoised image. According to the method and the system, the image denoising quality and efficiency can be ensured.