Abstract: A novel algorithm both for restraining intensive interferences and for estimating weak signals' DOA(Direction Of Arrival) information is presented on the basis of uniform linear array. Under the assumption knowing the number and directions of intensive interferences, first, the algorithm forms the beam on the sub-array level with the improved beam-forming method to constrain interferences; then, the algorithm estimates weak signals' DOA information based on all of these weighed sub-arrays. When both the desired signal and the interference are in the same beam, the merit of this algorithm shows higher estimation accuracy than that of high-resolution methods without improving the SNR for weak signal. Both the theoretical analysis and computer simulation indicate that the algorithm is effective.