Abstract: The present application relates to use of Prussian blue nanoparticles in the preparation of a medicament for the prevention, delay or treatment of neurodegenerative disease. The present application finds that Prussian blue nanoparticles have significant effects in the prevention, delay or treatment of neurodegenerative disease. Cell test results show that Prussian blue nanoparticles can reduce the level of ROS in nerve cells stimulated by hydrogen peroxide and increase the proportion of living cells in nerve cells stimulated by hydrogen peroxide. Animal test results show that Prussian blue nanoparticles can significantly reduce the expression level of oxidative stress markers in the hippocampus of mouse models of neurodegenerative disease, and significantly improve the learning and memory abilities and ameliorate motor dysfunction of mouse models of neurodegenerative disease.