Abstract: In order to solve the problems that the computation load of the dominant mode rejection (DMR) algorithm in array element domain increases sharply when the number of array elements getting large, and that the performance of the algorithm degrades when element spacing mismatching, a beam-space dominant mode rejection (BDMR) algorithm is proposed. The Algorithm transforms the array element space to the beam space to realize the dimensionality reduction calculation. The algorithm has faster calculation speed and better robustness while preserving the good performance of the original algorithm. Simulation result proves its validity and superiority.