Novel enzyme mimic materials with excellent analytical properties and stable structure are essential for detecting H2O2 in many fields. In the present work, we prepare PtNi alloy/CeO2 plates/N-doped carbon nanofibers (PtNi/CeO2/NCNFs) via heat-treating the electrospun nanofiber hybrid of polyvinyl pyrrolidone and inorganic metal salts. Structural analysis indicate that PtNi alloy nanoparticles disperse on or around CeO2 nanoplates and PtNi alloy/CeO2 plates uniformly embed in porous NCNFs. A possible formation mechanism of PtNi alloy/CeO2 plates in NCNFs is put forward based on the electrostatic interaction of Ce3+, PtCl62- 6 and Ni2+. The special structure of PtNi/CeO2/NCNFs can initiate the synergistic effect and enhance its enzyme-like electrocatalytic activity toward the reduction of H2O2. The PtNi/CeO2/NCNFs-based sensor displays outstanding performances for H2O2 detection with wide linear range of 0.5 mu M-15 mM, high sensitivity of 345.0 mu A mM(-1) cm(-2), low detection limit of 0.025 mu M, high selectivity and anti-interference. Besides, the sensor possesses superior reproducibility and good stability. The RSD value of response current obtained from five parallel experiments is evaluated to be 2.36% and PtNi/CeO2/NCNFs-GCE can still remain 98.5% of the initial response current value after being stored at 25 degrees C for 15 days. More importantly, the constructed sensor can be applied to detection of H2O2 content in cosmetics with satisfactory recovery (95.8%-103.8%) and low relative standard deviation (< 4.5%). These attractive properties make it possible for PtNi/CeO2/NCNFs to analyze H2O2 in real samples. (C) 2018 Elsevier Ltd. All rights reserved.