Polyvinyl Alcohol (PVA) can be used as an adhesive material, and it is less toxic than other synthetic adhesives. However, PVA has weaknesses in its mechanical properties. This research added additives such as Tannin Acid (TA) extracted from Gambier sap and Cellulose Nano Fiber (CNF) to enhance adhesive strength. The process of making bio adhesive materials in this research employed the torque mixing method. The mixing process between PVA, TA, and CNF was conducted with varying durations of 30, 60, 90, 120, and 150 min at a temperature of 30 °C and a rotation speed of 1500 rpm. Mechanical properties testing included shear testing, and physical properties were evaluated through density testing, FTIR analysis, and Scanning Electron Microscope (SEM). In this study, the adhesive material manufacturing process, using the mixing method for 90 min at a temperature of 30 °C and a rotation speed of 1500 rpm, yielded the highest adhesive shear strength at 3.47 MPa. The experimental results demonstrate that the bio adhesive derived from PVA/TA/CNF, manufactured through a straightforward process, enhances mechanical performance compared to synthetic structural adhesives. Consequently, the bioadhesive proves to be a promising candidate for integration into structural applications.