The Foldable Capsular Vitreous Body (FCVB) is an implantable vitreous substitute designed to provide internal tamponade in eyes with complex vitreoretinal conditions. This protocol describes a standardized surgical procedure for FCVB implantation via a scleral incision, followed by silicone oil injection. The protocol outlines key preoperative considerations, including patient selection and device sizing, followed by detailed intraoperative steps, including capsule folding, insertion into the vitreous cavity, controlled silicone oil injection, device positioning, and scleral fixation. Postoperative management strategies, including patient positioning, medication regimens, and follow-up evaluation, are also described to support procedural reproducibility. This protocol is intended for adult patients aged 18 to 65 years, with no sex-related restrictions. Eligible subjects must have a best-corrected visual acuity of less than 0.05 in the treated eye, an ocular axial length ranging from 16 to 28 mm, and present with severe retinal detachment that cannot be effectively managed using currently available vitreous substitutes. Previous clinical studies have reported that FCVB implantation can reduce silicone oil-related complications, such as emulsification and secondary glaucoma, by physically isolating silicone oil from intraocular tissues. These reported outcomes provide the clinical rationale for the use of FCVB but are not generated by this protocol itself. By presenting a step-by-step surgical workflow and highlighting critical technical considerations, this protocol serves as an instructional guide for vitreoretinal surgeons seeking to perform FCVB implantation or adapt the technique to their own surgical settings.