It’s showed that the real array could be virtually expanded by the higher order cumulants (HOC). So many DOA algorithms were proposed, such as MUSIC-LIKE, VMUSIC, and VESPRIT etc. Nevertheless, the mentioned algorithms were difficult to be applied in practice on the assumption that known was the signals number. In the paper study a robust virtual DOA algorithm to smooth away the problem. The new algorithm could form the noise subspace of fixed dimensions by the fourth order cumulants matrix and obtain the estimate of a substitute DOA set containing DOA of signals. From the substitute DOA set, the new one could get the estimate of true DOA. Computer simulation tests showed that the new algorithm could get better estimate of DOA as well as the signals number.