Abstract：The anode output efficiency is the fundament and key to determine whether bioelectrochemical systems (BESs) can be used for engineering application. However, the inefficient electron transfer at the microbe/anode interface hinders the further improvement of the overall output efficiency of BESs. In this study, a biomimetic graphene/hemin (GN/Hemin) composite was synthesized to simulate cytochrome c, thereafter was used to modify the anode of BESs. By monitoring the current generation of the electroactive bacterium Shewanella loihica PV-4, the effect of the biomimetic coating on promoting electron transfer at the microbe/anode interface was confirmed. The results showed that the maximum current density of the GN/Hemin modified anode was 7.28 μA·cm-2, which was 10.2 times higher than that of unmodified anode (0.65 μA·cm-2). Electrochemical analysis showed that the GN/Hemin coating significantly reduced the charge transfer resistance of the microbe/anode interface but improved the electrochemical catalytic activity of the anode. Furthermore, the GN/Hemin coating restored the current generation of the Geobacter sulfurreducens current generation deficient mutant strain (Gs-ΔomcZ), indicating that GN/Hemin has an OmcZ-like function. This study provides a facile anode modification strategy using biomimetic coating to construct high-performance BESs. Meanwhile, considering the unique high conductivity of OmcZ, the discovery of the OmcZ-like function of graphene/heme coating has important scientific and application value.