We　present　a　spectrum　filtering　approach　for　reconstruction　of　off-axis　digital　holograms.　The　high　frequency　aliasing　terms　in　Fourier　spectrum　domain　of　hologram　are　generated　by　non-fitting　interpolation.　After　interpolation　processing,　the　zero-order　terms　in　the　aliasing　spectrum　region　are　obviously　suppressed.　Accordingly,　for　the　spectrum　filtering　of　high-frequency　signal　terms,　the　available　range　of　frequency　band　will　increase　significantly,　which　can　result　in　the　improvement　of　resolution　of　the　reconstructed　images.　In　order　to　avoid　the　effect　of　non-uniform　distribution　on　the　aliasing　spectrum　terms,　all　the　same-order　signal　terms　in　the　aliasing　spectrum　(positive　or　negative　first-order　spectrum)　are　intercepted,　respectively,　and　then　added　together　to　reconstruct　the　complex　amplitude　distribution　of　the　sample.　We　perform　the　reconstruction　imaging　with　a　conventional　method　and　the　presented　method　from　the　same　hologram　in　simulation.　The　imaging　results　show　that　such　interpolation　method　can　obviously　improve　the　resolution　of　the　reconstructed　amplitude　and　phase　images.　This　method　for　off-axis　digital　holographic　reconstruction　only　relies　on　a　single　frame　acquisition　to　achieve　high　resolution　reconstruction　imaging　without　additional　requirements　to　the　optical　setup,　which　will　have　a　promising　application　in　real-time　imaging　for　living　biological　cells　or　moving　objects.