Abstract: For compact uniform circular arrays (UCAs), a novel method for multipath signals’ 2D DOA estimation in the presence of mutual coupling is presented. Based on the rand reduction theory(RARE), this method decoherents the multipath coherent signals, and compensates the elevation-dependent mutual coupling, then changing uniform manifold into new beam space array manifold and constructing two independent function of elevation angle and azimuth angle, realizes the estimation of azimuth angles in the presence of unknowing mutual coupling based on the relation between elevation angle function and noise vector null space by 1D parameter search, Finally, 2D DOA estimation is obtained through matching estimation results. Without aperture loss and preknowing the numbers of multipath signals, the estimation process only need 1D parameter search, meanwhile, can match the azimuth angles with elevation angles exactly, overcome the problem of fake 2D DOA estimation in RERE theory whose computation cost is as much as the new proposed algorithm. Simulation results validate the availability of the method.