Abstract: The dimension reduction quaternion estimation of signal parameters via rotational invariance techniques (DRQ-ESPRIT) algorithm has "quaternion model coherence" and aperture loss problems. The fake virtual symmetrical aperture expansion Q-ESPRIT (FVSAEQ-ESPRIT) algorithm is proposed to improve the DRQ-ESPRIT algorithm in this paper. The proposed algorithm solves the "quaternion model coherence" problem by switching the multiplication sequence between the electromagnetic expression and spatial steering vector. Meanwhile, symmetrical operation of steering vector and Khatri-Rao subspace process are utilized to increase the degrees of freedom of the polarization sensitive array, so that the estimation accuracy of direction of arrival (DOA) and polarization parameters is improved. Finally, the simulation results show the effectiveness of the proposed algorithm.