Improving the utilization efficiency of platinum (Pt) is required for realizing the efficient oxygen reduction reaction (ORR) in rechargeable Zn–air battery (ZAB). Herein, a carbon fiber decorated with coexistence of uniformly dispersed Pt nanoparticles and Pt-N-C moieties (Pt-HPCF) is synthesized and used as electrocatalyst for ORR. The elaborately structural design of Pt-HPCF catalyst on atomic/nanoscopic, mesoscopic and macroscopic level guarantees highly accessible activity sites, fast reactants transport, rapid electron transfer, and strong metal-support interaction. Benefited from the multi-level synergistic optimization, this unique Pt-HPCF electrocatalyst with ultralow Pt loading presents excellent ORR activity with a mass activity of 912.08 mA mg−1 at 0.85 V, which is 7.5 times that of the corresponding value for commercial Pt/C catalyst. Moreover, Pt-HPCF also exhibits high stability after accelerated degradation test. Furthermore, ZAB assembled with Pt-HPCF catalyst exhibits a high open circuit voltage (OCV) of 1.576 V, high capacity of 840 mAh g−1 at 5.0 mA cm−2, and a large peak power density of 163.38 mW cm–2. This work provides a feasible route for optimizing the Pt or other metal-based electrode in energy storage/conversion fields.