Abstract BACKGROUND Soy protein isolate is often used to make adhesives. Inspired by the adhesion mechanism of mussel proteins, this study developed a plant‐based adhesive composed of soy protein isolate (SPI), low‐ester pectin, tannic acid (TA), and transglutaminase (TGase) for bonding simulated fat and muscle in plant‐based meat analogues. RESULTS The results demonstrated that TA enhanced the viscosity, thermal stability, and fluidity of the adhesive by forming a cohesive network. Structural analyses revealed that covalent interactions between SPI and TA peaked at 2.5 wt%. The apparent viscosity results demonstrated that the TA concentration had a significant effect on the viscosity of the adhesive, lower concentrations (0–1.0 wt%) reduced the viscosity of the adhesive, whereas higher concentrations (1.5–3.0 wt%) increased it. Tensile adhesion tests showed that the mechanical properties of the adhesive reached their optimum value when the TA content was 2.0 wt%. Thermodynamic analysis indicated that TA improved the stability of the adhesive and reduced heat loss; however, excessive TA (3.0 wt%) led to aggregate formation, weakening the binding force between TA and protein molecules, and decreasing the thermal stability of the adhesive. CONCLUSION Tannic acid content is a key factor affecting the viscosity, thermal stability, and fluidity of SPI/TGase/pect in/TA (SPTTA) adhesives. This study provides a new formulation and methodology for the development of plant‐based adhesives for meat products. © 2025 Society of Chemical Industry.