Abstract: The real-life sea clutter of a certain range bin is analyzed by Wavelet Transform Modulus Maxima (WTMM) method and Multifractal Detrended Fluctuation Analysis (MFDFA), meanwhile, Time-Range bin-Amplitude plot method is presented in this paper to analyze the sea clutter of many range bins datasets, the results indicate that sea clutter is multifractal, when the sea clutter contains a small target, fractal is disturbed, so the multifractal characteristics is varied a lot. We also find that when Rényi parameter q<0, the generalized fractal dimension (GFD) of the range bin hosting a small target is obviously much larger than that of the range bin hosting no target, when q>0, this law is not obvious, upon this point, an algorithm based on difference between generalized fractal dimensions (DGFD) of different range bins is derived to detect a small target within sea clutter, the experiment results indicate that this algorithm is validate.