Neurodegenerative diseases (ND) are characterized by gradual loss of selectively susceptible neuron populations, usually presented by cognitive disorder and movement ability impairment, and cause great distress to patients and those close to them. The diagnosis and rehabilitation of NDs have been an unsolved challenge for many years, but brain-computer interface (BCI), a vigorously growing research area, may provide a promising tool to solve the problems. Here, we first briefly introduced the working principle of BCI, then take a few of the most common neurodegenerative diseases as an example to introduce the nowadays BCI application on NDs diagnosis and rehabilitation. This article will help researchers to gain a general understanding and appreciation of this field, and provide assistance for related studies.