The present invention provides a compound with a structure represented by general formula I or a pharmaceutically acceptable salt thereof, a preparation method for the compound or the salt, and a use of the compound or the pharmaceutically acceptable salt thereof in the preparation of medicaments for treating nervous system diseases, such as epilepsy, convulsion, neuropathic pain, acute ischemic stroke or neurodegenerative diseases. Compared with Retigabine, the compound of the present invention has better brain tissue absorption. Moreover, the compound provided by the present invention not only has greatly improved efficacy, but also has far fewer neurological side effects than Retigabine, and therefore has a wider safe window.
