The invention relates to a method for estimating a target azimuth formed based on phase difference beams, which is technically characterized by comprising the following steps: carrying out DFT operation for signals received by each array element to acquire frequency spectrums of the signals received by each array element at narrowband incident source center frequency; according to delay weighing P=W*V, carrying out phase matching for the acquired frequency spectrums in the forming direction theta d of the designated beam; according to BPDBF(theta)=1/(max(ang (P) ) -min (ang(P) ), calculating phases of the frequency spectrums of the array elements after the phase matching to obtain a spatial spectrum estimating graph, wherein ang (*) is phase operation; repeating steps 2 and 3 under different search angles theta to acquire spatial spectrum estimating graphs under the different search angles theta; and determining an angle corresponding to N spectrum peak values in the spatial spectrum estimating graphs as the target incident azimuth, wherein the N is the number of targets. The phase difference beam forming method can provide the peak value nearby a real angle so as to successfully distinguish incident double sources and provide the target azimuth.