Abstract: In order to realize the precise alignment of a two mirror optical system, a method using wavefront aberration measurement technique is introduced to accurately measure misalignment. The equations between the designed optical parameters, misalignment values and the wavefront aberration of misaligned optical system were established using vector wavefront aberration theory. The interferogram of a field of view was obtained through interferometry, and Zernike coefficients representing third-order coma and third-order astigmatism of misaligned system were obtained using fringe analysis software. Finally, Zernike coefficients were substituted into the equations to solve the misalignment values. The alignment of a 4 meter aperture RITCHEY-CHR-TIEN astronomical telescope was simulated. The solved misalignment values were fitted to the introduced misalignment values, and the accuracy of the method was proved.