Abstract: To solve the alignment for the offaxis mirror with more variable and high sensitivity, we introduced the computeraided interferometry technology, built the relationship between the misalignment and primary aberration, as well as the mutual compensatory relationship of each element.Moreover,we accomplished the systematic assembly and adjustment efficiently and speedily by collecting systems wavefront aberration through interferometry, obtained the misalignment of each element through the reverse optimizing analysis.Results show that the final wavefront error of the afocal compressed optical path system is better than 0.055 RMS at = 632.8 nm across all image plane, and the compression ratio is less than 5.