The invention relates to an orthogonal codon co-frequency multi-beam separation method based on a DS-CDMA system, and belongs to the technical field of digital signal processing. The method can separate co-frequency beams outputted among all array element channels in a multi-beam network, and solves the relation among the amplitudes and phases of all beam components. The method employs a PN code with the completely orthogonal property to carry out matching filtering and multi-user detection at a receiving end, can guarantee that the precision of amplitude and phase measurement is just limited by internal noise of a receiver and is not limited by multi-address interference.