Objective To study the effect of poly- DL- lactic acid (PDLLA) absorbable membrane on preventing adhesion after repair of peripheral nerve injury. Methods 60 SD rats were divided into 2 groups randomly: the suturing+ PDLLA group (experimental group) and the purely suturing group (contrast group), with 30 rats in each group. Their sciatic nerves were cut off and then sutured microsurgically. In the experimental group, the anastomotic stoma was encapsulated with PDLLA membrane; in the contrast group, there was no such a treatment. We conducted gross observations and histological examinations at 2, 4, 8, 12, and 16 weeks after operation, neural electrophysiological examinations at 12 and 16 weeks after operation, and image analysis by computer at 16 weeks after operation. Results The scar proliferation and adhesion near the anastomotic stoma in the experimental group were less extensive than those in the contrast group; regenerative nerve fibers grew more straight and orderly manner. Electrophysiological examinations and image analyses by computer also showed that the experimental group achieved better results than the contrast group. Conclusion Poly- DL- lactic acid (PDLLA) absorbable membrane can prevent scar proliferation and adhesion after repair of peripheral nerve and promote nerve functional recovery effectively.