The invention discloses an image defuzzification method based on Fourier transform. The method comprises the following steps: 1, by use of a k-svd algorithm, pre-denoising an input fuzzy image; 2, initializing a fuzzy kernel operator and dimension parameters; and 3, by taking change values of the dimension parameters as iteration termination conditions, performing internal iteration operation on the pre-denoised fuzzy image so as to obtain an image matrix after processing, according to the processed image matrix, updating the fuzzy kernel operator, and by taking preset frequency as an iteration termination condition, by use of the updated fuzzy kernel operator, performing external iteration operation on the processed image matrix so as to obtain a final denoised image. According to the image defuzzification method, the image is denoised first of all, then an estimation result is continuously optimized by use of an iteration method, and rapid convolution operation is finished by use of the Fourier transform, such that the calculation efficiency is improved, and too much prior arts about the image are unnecessary.