Antarctic krill (Euphausia superba) protein, as a type of high-quality protein resources, exhibits favorable bio-compatibility, environmental stability and other beneficial biological values. Nevertheless, the inadequate exploitation and low-value applications have impeded its development in the food industry. Based on the excellent amphiphilic structure of it, Antarctic krill protein, is expected to become a new material for constructing nutrient delivery system. In this study, salt-soluble Antarctic krill protein was used as carrying material to facilitate the delivery of astaxanthin hydrophobic nutrient factors by ultrasonic crushing and self-assembly. The micro-structure, bio-compatibility and antioxidant properties of astaxanthin nanoparticles were characterized and analyzed, so as to expand the application of Antarctic krill protein toward the field of nutrient delivery. The results showed that the astaxanthin nanoparticles prepared on the basis of salt-soluble Antarctic krill protein were spherically distributed, with favorable water solubility and thermal resistance. Furthermore, astaxanthin nanoparticles could enhance the biocompatibility of astaxanthin, and exhibited superior performance to free astaxanthin in inhibiting H