Based　on　the　balanced　detection　and　stationary　wavelet　transform　(SWT)　algorithm,　a　broadband　low　coherent　white　light　source　with　center　wavelength　of　700　nm　was　employed　to　set　up　a　time-domain　optical　coherence　tomography　(TDOCT)　system　in　free　space.　The　resolution　of　the　developed　OCT　system　was　down　to　0.93　μm　and　it　was　applied　to　nondestructive　evaluation　of　plastic　sheets　and　transparent-tape　multi-layered　thin-film　structures.　The　imaging　enhancement　methods　in　the　process　of　OCT　images　were　compared.　To　resolve　the　problem　of　unsatisfactory　reconstruction　results　using　current　algorithms,　the　SWT　decomposition　algorithm　was　introduced　to　deal　with　the　OCT　images　of　the　multi-layered　structures.　The　experimental　results　show　that　this　SWT-based　method　could　extract　more　distinct　interface　interference　signal　from　the　SWT　detail　coefficients　and　therefore　the　interface　imaging　quality　of　multi-layered　structures　could　be　enhanced.　©,　2015,　Editorial　Board,　Journal　of　Applied　Optics.　All　right　reserved.