Abstract: Carbon nanotube (CNT)/epoxy resin can be widely used to bond advanced structural parts in the aerospace field due to its excellent mechanical and bonding properties. However, how to effectively reduce the agglomeration of carbon nanotubes and ensure low cost and environmental protection of the preparation process is the key to the practical application of the nano-binder. Therefore, this paper proposes a protein dispersed carbon nanotube reinforced epoxy resin adhesive and investigates its bonding performance. The results show that the soy protein isolate (SPI) after a certain acid or alkali denaturation treatment can effectively reduce the agglomeration of carbon nanotubes and significantly improve the bonding performance of epoxy resin. When the CNT loading is 0.1wt%, the bonding property of acid and alkali treated SPI-CNT/epoxy is increased by 26.6% and 26.7%. While the CNT loading increases to 0.3wt%, the bonding property enhancement of the two treated methods comes to 10.2% and 18.3%, the alkali method is 79% higher than the acid one.