A conjugated polymer fluorescent probe was synthesized by Schiff reaction using the compounds of p-phenylenediamine and 1,10-phenanthroline-5,6-dione prepared with 1,10-phenanthroline.This polymer was characterized by means of 1H NMR,IR,viscosity,etc.The selective and sensitive properties of the polymer to detect metal ions were investigated by UV-vision absorption and fluorescent spectroscopy.Furthermore,in order to explore the interaction mechanism between the polymer fluorescent probe and Fe3+，the UV-Vis absorption and fluorescent spectra and IR absorption spectra of 1,10-phenanthroline-5,6-dione and polymer fluorescent probe at the presence and absence of Fe3+ were measured and analysed.The experiment results showed that the colours of the solution changed from colourlessness to reddish brown only at presence of Fe3+,which indicating that Fe3+ could be detected by naked eyes.Moreover,the change of the UV-vision absorption and fluorescent spectra of the polymer revealed that the polymer fluorescent probe owned a high sensitivity and selectivity for the detection of iron(Ⅲ).The instant response time was less than 1 s,and the abslute response time was 30 min.Moreover,the linear response range of iron(Ⅲ)was in the range of 0-12.5 μmol/L and the detection limit was 2.72 μmol/L.The quenching constant of Fe3+ to the probe was 1.52×104 L/mol.In addition,the possible interactional diagrammatic sketch between the polymer fluorescent probe and iron(Ⅲ)was drawn by analysing the interactional mechanism of the polymer probe-Fe3+ complex.