Hydrogen peroxide (H 2 O 2 ) is one of the intermediates or final products of biological metabolism and participates in many important biological processes of life activities. The detection of H 2 O 2 is of great significance in clinical disease monitoring, environmental protection, and bioanalysis. In this study, Ti 3 C 2 -based nanohybrids are prepared by the biological modification and self-assembled peptide nanosheets (PNSs)-based biomimetic synthesis of copper sulfide nanoparticles (CuS NPs), which show potential application in the fabrication of low-cost and high-performance electrochemical H 2 O 2 biosensors. The synthesized CuS-PNSs/Ti 3 C 2 nanohybrids exhibit excellent electrochemical performance towards H 2 O 2 , in which CuS NPs can catalyze the decomposition of H 2 O 2 and realize the transformation from a chemical signal to an electrical signal to achieve the purpose of H 2 O 2 detection. The prepared CuS-PNSs/Ti 3 C 2 -based electrochemical biosensor platform exhibits a wide detection range (5 μM-15 mM) and a low detection limit (0.226 μM). In addition, it reveals good selectivity and stability and can realize the monitoring of H 2 O 2 in a complex environment. The successful biomimetic synthesis of CuS-PNSs/Ti 3 C 2 hybrid nanomaterials provides a green and friendly strategy for the design and synthesis of functional nanomaterials and also provides a new inspiration for the construction of highly effective electrochemical biosensors for practical detection of H 2 O 2 in various environments.