A flexible carboxylic ligand,1,4-benzenebis(thioacetic acid)(H2L),has been employed to assemble with Cd(Ⅱ) ions under hydrothermal conditions,generating a new complex [Cd2L2(2,2'-bipy)2]n(1).X-ray diffraction reveals the complex 1 possesses a self-assembly double helix structure deriving from [Cd2L2(2,2'-bipy)2] units linked by L2ligands.A 3D infinite framework is constructed via π-π stacking of 2,2'-bipy.The photoluminescent properties in solid state were investigated.