Flexor digitorum profundus of adult Leghorn hens was used in the experiment. METHODS the long flexor tendons were cut and sutured with sheath excised between A2 and A4. Experimental group: the biological membrane was placed circumferentially around the repair site to reconstruct the flexor sheath after flexor tendon repair. The tendon healing, the adhesions and the development of pseudosheath were examined by naked eyes, optical and electron microscopy respectively. It was proved that the membrane not only could separate the healing flexor tendon from the surrounding tissue and reduce adhesion, but did not cause any local and systemic adverse reaction. The results showed that the development of the new tendon sheaths around the biological membrane was similar to silastic prosthesis in morphology. The pseudosynovial sheath supplied good tissue bed for tendon gliding. It was found that the stimulation of the membrane to the surrounding tissue was the basis of new sheath formation in the early stage and tendon gliding in the late stage would promote the pseudosheath to be mature and stable. Therefore, the results provided experimental basis for clinical practice.