In the background of sea clutter,it is difficult to detect small targets on sea surface,and the traditional Fractional Fourier Transform (FRFT) algorithm has unstable detection performance,large computation amount and low detection efficiency.To solve the problems,a new fast algorithm for detecting small targets in sea clutter is proposed.CEMD-RobustICA denoising algorithm is used to suppress sea clutter,so as to weaken its influence on the performance of Bi-orthogonal Fourier Transform (BFT) and Concise Fractional Fourier Transform (CFRFT).BFT-CFRFT algorithm is used to detect small targets, which transforms the two-dimensional search of the traditional algorithm into two one-dimensional searches,so that the amount of computation is greatly reduced.IPIX measurement data is used to verify the new algorithm,and the experimental results show that:1) The new algorithm can effectively suppress sea clutter,greatly reduce the amount of computation,and improve the accuracy and timeliness of target detection with the best performance in HH polarization conditions;2) The new algorithm has high detection efficiency and stable performance,which can be widely used in practical projects.