Adhesion formation between dura mater and the overlying temporalis muscle following decompressive craniectomy can make subsequent cranioplasty difficult and adds to the risks of the procedure. In this work, we developed an electrospun PCL-gelatin hybrid membrane to be planted at decompressive craniectomy for preventing adhesion formation and facilitating subsequent cranioplasty. We prepared poly(ε-caprolactone)-gelatin (PG) nanofiber membranes with different PCL-gelatin ratios. The architectural features, mechanical properties, cell barrier functions, in vivo degradability, biocompatibility and anti-adhesion function were investigated. All membranes were found to have high tensile strength, and the strength of the membranes improved with the PCL content increased. All the PG membranes presented good biocompatibility and cell isolation performances while an increase in the gelatin content resulted in an enhancement of cell adhesion and proliferation. Subcutaneous implantation in rabbits for 6 months demonstrated that all the membranes showed good biocompatibility and adjustable biodegradation behaviour. In rabbit cranial defects model, no adhesions were observed, either between the PG membranes and the dura, or between the membranes and the temporal muscle after 1 month implantation. PG membranes' anti-adhesive properties and biodegradable characteristics make it useful as a dural onlay for craniotomy in which a second surgery is planned.