Thickness　measurement　using　spectral　domain　optical　coherence　tomography　(SD-OCT)　has　been　increasingly　applied　in　semiconductor　manufacturing　due　to　its　advantages　of　nanometer-level　accuracy,　millimeter-level　measurement　range,　and　high　efficiency.　High-precision　thickness　measurement　not　only　requires　the　technology　itself　to　have　extremely　high　measurement　accuracy,　but　also　must　reduce　the　influence　of　external　errors.　Abbe　second-order　error　(ASE)　is　widely　present　in　thickness　measurement,　and　when　the　measurement　accuracy　approaches　the　nanometer-level,　we　must　consider　and　reduce　the　impact　of　ASE　on　thickness　measurement.　In　this　work,　we　conducted　an　in-depth　analysis　of　ASE　that　arises　when　using　SD-OCT　for　rotational　scanning　thickness　measurement.　We　quantitatively　analyzed　the　influence　of　ASE　on　thickness　measurement　from　both　simulation　and　experimental　perspectives　by　establishing　a　mathematical　model　and　conducting　a　sapphire　thickness　measurement　experiment.　Meanwhile,　we　proposed　a　thickness　correction　method　to　reduce　the　influence　of　ASE　on　thickness　measurement.　The　experimental　results　show　a　high　degree　of　consistency　with　the　simulation　analysis.　The　average　thickness　of　the　sapphire　substrate　before　correction　is　270.706　µm,　the　value　after　correction　is　270.583　µm,　and　the　average　ASE　correction　amount　is　123　nm.　The　proposed　method　effectively　reduces　the　impact　of　ASE　on　thickness　measurement,　which　is　of　great　significance　for　achieving　thickness　measurement　with　nanometer-level　accuracy.　©　2025　Elsevier　Ltd