Abstract: In multiple input multiple output（MIMO）radar,Due to the practical degradation performance of propagator algorithm in the low signal to noise ratio and a small number of snapshots environment for 2-D direction of arrival estimation for targets,An improved propagator is proposed in 2-D DOA estimation.In the proposed algorithm,conjugate data reconstruction thought is applied to estimate the propagation operator and the rotation invariance of the propagator is used in direction matrix estimation,and then we get the 2-D angles information by the direction matrix,According to the matrix change and structure feature,we realize the automatic matching of elevation and azimuth angles.Complexity analysis and simulation results show that the algorithm have low complexity,and the PM algorithm performance is improved when snapshot number is limited and in low SNR,and we realize the automatic matching of 2-D direction of arrival at the same time.