Due to their exceptional bioadhesive properties and potential biocompatibility, high-viscosity protein materials exhibit significant application prospects in the fields of biomedical materials and adhesives. However, traditionally sourced high-viscosity protein materials encounter numerous challenges, including low yields, structural complexity, and difficulties in scaling up production. Synthetic biology, as an emerging interdisciplinary field, offers innovative strategies to address these bottlenecks. This review systematically summarizes recent advances in the biosynthesis, modification, and applications of high-viscosity protein materials, focusing on the advantages of synthetic biology in addressing issues related to the yield, controllability, and functional diversity of these materials. The precise design and efficient expression of adhesive proteins, such as mussel adhesive proteins, barnacle cement proteins, and scallop foot proteins, achieved through genetic engineering, are comprehensively reviewed, demonstrating the overcoming of limitations in the production and controllability of high-viscosity protein materials. Furthermore, the unique advantages of these protein materials in bioadhesives and functional medical coatings, such as the wet adhesion of mussel proteins, the strong adhesion of barnacle cement proteins, and the tunable properties of elastin-like proteins, are summarized. By employing synthetic biology approaches, limitations in the yield, performance, and functionality of high-viscosity protein materials can be overcome, thereby accelerating their application in areas such as tissue engineering and surface modification. Finally, the latest advancements and innovations in the field of synthetic biology for high-viscosity protein materials are summarized, and future development directions are envisioned, offering new ideas and strategies for the development of high-performance, multifunctional high-viscosity protein materials.