Digital　holography　is　the　product　of　the　optical　holography,　computer　technology　and　photoelectric　detection　technology,　and　has　the　advantage　of　high-speed,　real-time,　full　field　of　view,　non-contact　and　quantitative　phase　contrast　imaging.　However,　the　numerical　aperture　of　the　hologram　is　limited　due　to　the　smaller　sensitive　area　of　the　photoelectric　sensor　and　the　larger　pixel　size,　and　it　is　uneasy　to　meet　the　practical　requirement　on　the　imaging　resolution.　An　approach　is　presented　to　achieve　the　high-resolution　digital　holographic　imaging　based　on　a　spatial　light　modulator(SLM).　An　amplitude　spatial　light　modulator　is　placed　between　the　object　and　the　CCD　in　the　lensless　Fourier　transform　digital　holographic　imaging　system.　The　distribution　of　a　diffraction　grating　is　loaded　into　the　SLM.　In　this　way,　more　light　including　the　high-frequency　content,　diffracted　from　the　object,　can　be　collected　by　the　CCD.　The　standard　resolution　target　is　used　as　the　object.　The　reconstructed　image　is　obtained　by　the　Fresnel　diffraction　propagation　algorithm,　which　exhibits　three　diffraction　orders.　The　results　show　that　the　resolution　is　improved　from　62.5　mu　m　to　31.3　mu　m.