Aimed at the problems that the traditional algorithm is low in efficiency and low in accuracy of the direction of arrival (DOA) estimation in coherent targets under conditions of strong interference background, on the basis of constructing the interference blocking matrix to eliminate strong interference in a specific direction, a DOA estimation of coherent targets is made based on the local spatial difference algorithm. First, the blocking matrix is constructed by the angle information of the received signal matrix to eliminate the strong interference information of the covariance matrix, and then the covariance matrix is divided into several submatrices using the local spatial difference algorithm, fully extracting the effective information. Finally, the linear operator method is utilized for completing the DOA of the target estimation. The algorithm effectively improves the data utilization. The simulations show that the proposed method is low in estimation deviation and high in success probability in comparison with the traditional algorithm under conditions of strong interference background.