Background Although epineurium neurorrhaphy is the most reliable and conventional method for the repair of peripheral nerve injury and is accepted as the gold standard, it is still far from ideal. Many attempts have been made to develop nerve anastomosis techniques. The aim of this study was to investigate the use of small gap anastomosis performed by cutting and sleeve jointing the epineurium for nerve repair. Methods A 12-week study was performed using small gap anastomosis via cutting and sleeve jointing the epineurium, compared with epineurium neurorrhaphy in situ, to repair a rat sciatic nerve rupture. Three experimental groups were included: sham control (n = 8), small gap anastomosis (n = 16), and epineurium neurorrhaphy (n = 16). About 12 weeks after surgery, recovery was assessed with walking track analysis, electrophysiology, hematoxylin and eosin staining, immunohistochemistry, and electron microscopy. Results The sciatic nerve functional index observed in the small gap anastomosis group was significantly higher than that in the epineurium neurorrhaphy group (p < 0.05). In vivo electrophysiological analysis confirmed that the small gap anastomosis group showed a significantly higher conduction velocity than the epineurium neurorrhaphy group (p < 0.05). Postoperative morphometric analysis revealed better results after small gap anastomosis compared with epineurium neurorrhaphy. Conclusion Small gap anastomosis via cutting and sleeve jointing the epineurium could be an alternative to epineurium neurorrhaphy for the repair of peripheral nerve injury, particularly, considering that the epineurium originates from native tissue that provides a suitable microenvironment for the selective regeneration of axons.