In order to solve the problem that the interference signal changes rapidly in the high dynamic environment and moves out of the null of the beam, which leads to the reduced performance of the anti-interference algorithm, a robust beamforming algorithm based on null broadening and deepening is proposed. The algorithm first set multiple virtual interference in the interference interval instead of a single interference, and then modified the covariance matrix by the covariance matrix forward and backward spatial smoothing technique. Simulation results show that the proposed algorithm can not only effectively widen and deepen the null in the direction of interference signal, but also make the array have good output signal to noise ratio, and still maintain strong robustness when the interference changes rapidly. The proposed algorithm has better performance than other algorithms so is more suitable for high dynamic environments.