The　three-step　or　many　steps　phase　shifting　method　is　usually　employed　to　resolve　the　complex-conjugate　ambiguity　in　Spectral-domain　optical　coherence　tomography　(SD-OCT).　However　it　reduces　the　image　quality　and　also　the　imaging　speed　is　slow.　In　this　paper　two　steps　phase-shifting　is　used　in　digital　image　processing　to　resolve　the　complex-conjugate　ambiguity　and　improves　the　quality　of　reconstructed　image　in　SD-OCT.　In　the　two-step　phase　shifting　method　the　phase　shifting　operation　is　used　only　once　which　simplified　the　experiment　and　also　the　effect　of　relative　error　in　SD-OCT　on　image　quality　is　eliminated.