Abstract: Since the adaptive beamformer suffers from the output performance degradation when the position of the interference moves, a new null broadening technique is proposed. The algorithm uses the projection technology to transform the array receives data, combined with diagonal loading techniques to get the new covariance matrix. The original covariance matrix is replaced by a new covariance matrix as such, and then a null broadening beam can be obtained using the adaptive beamforming technique. The simulations results show that this method can effectively broadening the beam null width and enhance the null depth, so the new algorithm can suppress strong interference with rapid movement; and the algorithm is easy processing, which can still work effectively even in the condition of low snapshot, the algorithm enhanced robustness of the beamformer.