In order to study the computer-aided alignment for the off-axis reflective zoom optical system, the wavefront aberration of the off-axis reflective zoom system across the field of view needs to be detected. Obtaining the wavefront aberration across the field of view could improve the accuracy of the computer-aided alignment for the off-axis reflective zoom optical system. Restricted by the current wavefront aberration detection technology, only the wavefront aberration at a field degree of 0 could be detected. To solve this problem, a new method to detect the wavefront aberration of off-axis reflective zoom system across the field of view is proposed. According to the traditional autocollimation interferometry method, we improve the detection method by substituting the scan of standard plane mirror with the deformable mirror, replacing the interferometer with Shark-Hartmann sensor and employing the accurately calibrated laser source array to realize the wavefront aberration detection at multiple field of view simultaneously. The simulation shows that the residual wavefront aberration root-mean-square values after compensating for the deformation mirror in the following 6 fields of view (0, 3), (0, 4.2), (0, 5.5), (0, 7), (0, 9.8), and (0, 14) are 0.00039, 0.00075, 0.00024, 0.00017, 0.00053, and 0.0057, respectively. It shows that the detection method we proposed is suitable for the computer-aided alignment technology for the off-axis reflective zoom system.