Abstract: In this paper a two-dimensional direction of arrival (DOA) estimation method for coherent signals is proposed. In this method, the conjugated matrix of the covariance matrix of the L-shaped array receiving data is reconstructed firstly, and then, by adding the square of the original covariance matrix to the square of the reconstructed conjugated matrix and taking the mean, a new covariance matrix is constructed. After the new covariance matrix being preprocessed with forward and backward array spatial smoothing techniques, the RootMUSIC algorithm is finally used to estimate DOA information. The simulation and lake trial data show that compared with the traditional method, the method proposed in this paper avoids searching spectral peaks, reduces computation amount, and improves the resolution success probability and the DOA estimation accuracy of the coherent signals. It has good engineering application value.