Metal-organic Frameworks (MOFs) are a kind of molecular-based functional materials that are highly structurally designed by connecting metal ions or cluster nuclei with organic ligands through coordination bonds. Metal-organic frameworks show attractive application prospects especially in new optical devices, and are expected to become environmentally friendly functional luminescent materials with great application value. Therefore, a colorless transparent crystal ［Mn4(OH)2(tpdc)3］·2CH3CN (1) was synthesized under solvothermal conditions using linear benzene-carboxylic acid ligand 1,4-bis (4-carboxyphenyl) benzene (H2tpdc). The compound was characterized by an X-ray single-crystal diffractometer, and its thermal stability and fluorescence properties were studied. Compound 1 crystallizes in the monoclinic P21/c space group. Each misalignment unit of the compound contains four Mn2+ ions and three H2tpdc2-ligand anions in an asymmetric unit. The crystal growth is a rhomboid two-dimensional layered structure. The excitation and emission spectra of the complexes were measured, and the fluorescence responses of the complexes to different metal ions in aqueous solution were investigated. The experimental results show that compound 1 can sensitively detect Fe3+, Cr2O2-7 and CrO2-4 ions from different ions. The detection limits of Fe3+, Cr2O2-7 and CrO2-4 were 8.2×10-7， 6.7×10-7, 9.2×10-6 mol·L-1, respectively.