A cadmium-based coordination polymer [Cd₄(L)₄(1,4-bib)₄]·2DMA (CP1) was synthesized under solvothermal conditions, where H₂L=2 hydroxyterephthalic acid, 1, 4 bib=1, 4 bis(imidazol1 ylmethyl) benzene, and DMA=N,N-dimethylacetamide. The structure was characterized by thermogravimetric analysis, elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction. The single crystal structure shows that CP1 belongs to the orthorhombic system, the space group Pna2₁, Cd(Ⅱ) forms a 2D plane structure through L^2-, and the 2D plane structure forms a 3D network with pcu topology through 1,4-bib. CP1 shows good fluorescence sensing performance and thermal stability and realizes efficient and sensitive detection of 2,4,6-trinitrophenol (TNP), Fe³⁺, and fluridine (FLU). The detection limits were 0.051 μmol·L^-1 (TNP), 0.65 μmol·L^-1 (Fe³⁺), and 0.14 μmol·L^-1 (FLU), respectively. In addition, the mechanism of fluorescence detection of pollutant detection was explored and a portable test paper was successfully prepared. A portable test paper could not only selectively detect FLU, but also showed different fluorescence colors in different concentrations of FLU.