Abstract: As the supplement for the current computer aided alignment method for the advanced optical system, surrogate model was proposed to represent the intricate relationship between the misalignment parameters and the aberration coefficients, so a new solution method of the misalignments could be carried out. At the beginning, the principle of the sensitivity matrix method was analyzed to show its limitation, and then the surrogate model was introduced as a new tool. Comparison of various surrogate models, the artificial neural network was chosen to represent the obscure relationship between the misalignment parameters and the wavefront error, while these data were collected by Monte Carol simulation in Zemax. In the end, an off axis three mirrors astigmatism system was taken as an example to illustrate the process of building the surrogate model and calculating the misalignment. All above procedures show the practicability and reliability of the surrogate method for the optical alignment, and it is more robust and quick than the conventional sensitivity matrix method.