Ru（bpy）,3,2+,－doped silica nanoparticles（RuSi NPs）， as one of the classical electrochemiluminescence（ECL） luminophores， not only simplify the immobilization process of Ru（bpy）,3,2+,， but also effectively improve the utilization rate of Ru（bpy）,3,2+,. However， the conductive inertness associated with Si significantly inhibits the electron transfer rate of Ru（bpy）,3,2+,， thereby significantly reducing the ECL emission efficiency of RuSi NPs， which， in turn，limits the application of RuSi NPs in ECL sensors. Herein， a kind of highly ordered flower-like hierarchical titanium dioxide micro-nanoparticles（fl-TiO,2,） with a uniform particle size approximately 5.0 μm were prepared by a solvothermal method. Furthermore， the amino-functionalized fl-TiO,2,（fl-TiO,2,-NH,2,） was synthesized by a simple post-synthesis grafting method using（3-aminopropyl） triethoxysilane（APTES） as the coupling agent. Subsequently， platinum nanoparticles（Pt NPs） were successfully assembled on the surface of fl-TiO,2,-NH,2, via electrostatic interaction to fabricate a new kind of fl-TiO,2,/Pt NP composites（fl-TiO,2,/Pt NPs）. Finally， fl-TiO,2,/Pt NPs/RuSi NPs hybrids were prepared by mixing fl-TiO,2,/Pt NPs and RuSi NPs in redistilled water to form a uniform dispersed solution， which were immobilized on the surface of glassy carbon electrode（GCE） to develop a novel ECL sensor（fl-TiO,2,/Pt NPs/RuSi NPs/GCE）. The morphologies， structures， physical properties， and chemical compositions of different materials were characterized using techniques such as scanning electron microscopy， UV－Vis absorption spectroscopy， X-ray diffraction， and energy spectroscopy. The electrochemical behavior and ECL performance of the proposed ECL sensor were also studied using cyclic voltammetry， alternating current impedance， and ECL techniques. The experimental results suggested that the ECL intensity of RuSi NPs－tripropylamine（TPrA） system enhanced significantly owing to the excellent electrocatalytic activity of Pt NPs， and the large specific surface area of fl-TiO,2, provided abundant binding sites for Pt NPs and RuSi NPs. Thus， the fl-TiO,2,/Pt NPs could be used as a novel ECL signal amplifier for enhancing the ECL emission efficiency of RuSi NPs－TPrA system. Under the optimized experimental conditions， the ECL intensity of fl-TiO,2,/Pt NPs/RuSi NPs was 1.5 and 1.8 times higher than that of fl-TiO,2,/RuSi NPs and pure RuSi NPs， respectively. Meanwhile， the stable ECL emission from fl-TiO,2,/Pt NPs/RuSi NPs－TPrA system could be strongly quenched by phenylephrine（PHE）. Based on the strong interaction between PHE and RuSi NPs， the designed ECL sensor demonstrated a wide linear range from 1.0 × 10,－7, to 8.0 × 10,－5, mol/L（,r,2, = 0.998 4） with a detection limit（,S,/,N, = 3） of 2.5 × 10,－8, mol/L for PHE， and it was successfully applied to the determination of PHE in phenylephrine hydrochloride injection with excellent long-term stability， good reproducibility， and high selectivity. The recoveries ranged from 99.2% to 108%. This work proposes a novel ECL signal amplification strategy for the construction of ECL sensing platform， which is anticipated to extend the applications of ECL sensors in drug analysis.