The present invention provides compounds having the structure represented by general formula I, pharmaceutically acceptable salts thereofagonist, preparation methods therefor and a use thereof in the preparation of a medcine for the treatment of nervous system diseases. The compounds or pharmaceutical compositions thereof can be used as the KCNQ potassium channel agonist for treating nervous system diseases. Compared to retigabine, a compound in the prior art, the compound of the present invention have the same or better therapeutic effect, are easier for synthesis and storage, and less prone to oxidate deterioration.
