The invention belongs to the array signal processing field and relates to a hexagonal array-based coherent signal two-dimensional DOA (Direction of Arrival) estimation method, in particular to a high-precision, de-coherence, two-dimensional signal DOA subspace estimation method. According to the estimation method of the invention, an array is virtualized and extended through performing conjugate matrix solution on array receiving data, so that a hexagonal array including three sub arrays are obtained, and then, a correlation matrix of a subspace algorithm is extended and reconstructed according to an autocorrelation matrix and a cross correlation matrix of the three sub arrays, and therefore, de-coherence can be realized; and singular value decomposition is performed on the new correlation matrix, so that a signal subspace and a noise subspace can be obtained, and then, DOA estimation is performed on coherent receiving signals through utilizing a two-dimensional MUSIC (Multiple Signal Classification) estimation method. With the estimation method of the invention adopted, coherence between source signals can be eliminated, and the estimation accuracy of two-dimensional DOA can be further improved. The estimation method is mainly applied to two-dimensional high-precision DOA estimation of coherent signals.