Nerve guidance conduit (NGC) serves as the most promising alternative to autografts for repairing long-range defects of peripheral nerves. In this study, we investigated whether modulating the immune microenvironment by Interleukin-17F (IL-17F) could promote NGC mediated peripheral nerve repair. Chitosan conduit were used to bridge sciatic nerve defect in IL-17F knockout mice with wild-type mice and autografts as controls. Our data revealed that IL-17F knockout mice had improved functional recovery and axonal regeneration of sciatic nerve bridged by chitosan conduits comparing to the wild-type mice. Notably, IL-17F knockout mice had enhanced pro-healing M2 macrophages in the NGC repairing microenvironment. In vitro data revealed that IL-17F knockout peritoneal macrophages had increased M2 markers after treatment with the extracts from chitosan conduits, while higher inflammatory M1 markers were detected in the Raw264.7 macrophage cell line and wild-type peritoneal macrophages after the same treatment. The biased M2 macrophage phenotype by IL-17F knockout probably contributed to the improved chitosan conduit guided sciatic nerve regeneration. These results not only revealed a role of IL-17F in macrophage function, but also provided a unique and promising target, IL-17F, to modulate the microenvironment and enhance the peripheral nerve regeneration.