To solve the problem of too large angle estimation error for radar under low altitude condition, a DOA estimation algorithm for low altitude target based on TR MIMO radar is proposed. Firstly, The focusing performance of TR technology is used in the proposed algorithm, obtaining the echo signal matrix. According to the waveform diversity of MIMO radar, The virtual subarrays of TR MIMO radar is deduced. Then, we perform rows and columns reuse and apply FBSS algorithm to remove the coherence, effectively improving the DOA estimation accuracy for low altitude target. The simulation results verify the validity of the method. The simulation results show that the RMSE of the proposed algorithm is reduced by an average of 0.3 degree compared with the conventional MIMO radar when the SNR is -10 dB.