Abstract: The desired signals can be reconstructed from the received sonar data without prior information by the blind beam-forming technique.In order to make full use of wide-band information,frequency decomposition technique is raised to get narrow-band signal from broadband signal.Then blind beam-forming algorithm named JADE is utilized to process the signal acquired.In this paper the algorithm is proved theoretically and examined through simulated data.Results show validity of the assumption.The blind beam-forming algorithm outperforms the conventional one.