Abstract:  MIMO radar obtains spatial diversity by distributed sensors, which are difficult for estimation of DOA. In this paper, sidelobes of DOA estimations are analysized,which are equal in some conditon. Commencing with signal model, virtual subarrays are designed through filters by transmitting orthogonal signals, and the Spectrum Selection(SPS) algorithm is proposed. The algorithm obtains the best estimations of all targets from every subarrary, and receives spatial diversity as well as robust super-resolusion direction-of-arrival estimation.At last the simulated results show that the SPS algorithm is effective and improves the performance of DOA estimations.