There is a common mechanism in the pathogenesis of central nervous system diseases: Neuronal damage causes a dissipation of the intermediate metabolites, triggering a wider range of injury and inflammation. Due to the selective permeability of the blood-brain barrier, the drug treatment of neurological diseases is not effective. Nanomedicine, with good biocompatibility and high plasticity, can pass through the blood-brain barrier through various mechanisms and targeted the lesion: The nano-delivery system helps drugs cross the blood-brain barrier while taking advantage of its high drug-loading capacity to achieve combined treatment; Nano-enzymes can simulate the enzymatic reaction in biological body to remove metabolic substances, and are more stable and economical than biological enzymes; Individual nanomedicine can regulate the differentiation process of neural stem cells from the genetic level, increase the number of neurons, and repair injured nerves. Nanomaterials can not only improve the pharmacokinetics and pharmacodynamics, but also play the function of focal location to monitor and evaluate the disease and condition during the treatment of nervous system diseases. In this paper, the mechanism of nanomaterials penetrating the blood-brain barrier (BBB) and locating lesions in various nervous system diseases is reviewed, which opens up new ideas for further exploring the application of nanotechnology in central nervous system diseases.