A method for clutter suppression of a ground penetrating radar based on degressively convergent image entropy, comprising the following steps of: 1) performing a short time Fourier transform on each reception signal in the horizontal direction of a ground penetrating radar B-scan graph, and calculating amplitude values and phase values; calculating a mean value of the amplitude values obtained bythe Fourier transforms on all signals, and subtracting the mean amplitude value from the amplitude value obtained by the Fourier transform on each signal; 2) taking the amplitude value corresponding to each signal obtained by the first step as an amplitude, and combining the phase value obtained by the Fourier transforms in the first step to perform an inverse short time Fourier transform; 3) obtaining a first processing result after going through step 1 and step 2; and 4) repeating step 1 and step 2, then adaptively weighting the each iteration result with the first processing result until that the weighting result ends the convergence and iteration of image entropy. Excellent clutter suppression effect can be obtained by using the method disclosed in the invention.