ing at the characteristic of the internal space limitation of the optical system of large aperture telescope, in order to realize the correction of the misalignment, a method for solving the misalignment based on the eigen coefficient is proposed. Firstly, based on the principle of wavefront curvature sensor, the light spot patterns are collected by alternately measuring the front and back defocused surfaces. Then, the wavefront is reconstructed by the eigenfunction method without partition detection, the eigen coefficients are used to characterize the system wave aberration,and the sensitivity matrix model is established according to the misalignments. Finally, the misalignments can be solved according to the eigen coefficients of the misalignment state and the ideal state. Compared with other technical approaches, this method has the characteristics of no need to add optical components, no partition detection, and simple operation. The experimental results by the telescope with the primary mirror diameter of 1.8 m show that when the eccentric distance range of the secondary mirror is from -0.9 mm to 0.9 mm and the tilt angle range is from -0.2° to 0.2°, the errors of the calculated values obtained by the eigen coefficient sensitivity matrix method are less than 10%, which has certain significance for the application of large aperture telescopes.