A novel fluorescent probe, which has an amphiphilic structure and can selectively detect and distinguish trivalent metal cations, was synthesized. The probe has a hydrophobic quinoline head and a hydrophilic pyridinium tail. This amphiphilic molecular structure makes the molecule exhibit ideal solubility and sensitivity in three kinds of solvents, including EtOH, CH₃CN and H₂O. The ideal cross-reactivity of this probe in different solvents provided it with the ability to distinguish Fe³⁺, Cr³⁺, Al³⁺, Ru³⁺ and Au³⁺ through the PCA method. The detection limits of the probe for trivalent metal cations reach the micromolar range.