The invention discloses a method for detecting median filtering based on frequency domain fluctuation characteristics. The method comprises the following steps: conducting DFT on an acquired original image to obtain a frequency domain image of the original image; processing the frequency domain image to obtain description points which can reflect frequency fluctuation characteristics of the original image, and dividing the processed image into N annular regions, and then separately conducting statistics on the total number of the description points of each annular region to obtain a constituted N dimensional detection characteristics; inputting the extracted N dimensional detection characteristics to a support vector machine for training to obtain a support vector machine median filtering detector, then the support vector machine median filtering detector detecting whether the original image undergoes median filtering. According to the invention, the method more directly reflects difference between image that undergoes median filtering and the original image, can accurately detect whether the image has undergone median filtering provided that a lower characteristic dimension can be maintained and the algorithm is simple, can achieve high detection accuracy, and has robustness.