The invention relates to a direction of arrival estimating method based on a rectangular antenna array. The array is capable of directly carrying out unambiguous 360-degree angle estimation on the direction of arrival, the array is an M*N rectangular array, and all antennas are omnidirectional antennas. According to the invention, a transverse antenna array and a longitudinal antenna array of the matrix array are utilized to respectively carry out direction of arrival estimation on signals, and the crossed part of the two times of estimation is utilized for unambiguous estimation. Only two times of linear array calculation are needed, the calculation complexity is low, the difficulty of software programming is lowered from the aspect of hardware realization, and the speed of hardware processing is substantially improved.