Abstract: The analysis of the target radiated noise model is made as a precondition under the background of fluctuating sound field firstly. A broad and narrow band integrated coherent detection algorithm based on phase fluctuation and differential alignment is proposed for the issue of target azimuth estimation and narrow-band line-spectrum detection. The background noise energy disturbances can be restrained by using the differences of temporal correlated radius and phase fluctuation uniformity for the periodic spectrum signals and broadband noise; The ability to identify different DOA targets can also be improved by combining phase fluctuation aligned gain of the output signal in focused beam domain and spatial coherent gain of the signal processing in array domain. It is proved that the proposed algorithm can significantly enhance the detection SNR gain of the target line spectral component and relative energy spectrum level of the coherent targets beam azimuth by analyzing the simulation and sea experiment results. It has better application prospects in the detection and identification areas of anti-complex channel.