Provided in the present invention are one class of pyrazolone compounds and a use thereof. In particular, provided in the present invention is a compound as represented by general formula I, wherein the definition of each group is as described in the description. The compounds of the present invention have a direct AMPK-activating activity and can significantly promote the phosphorylation of AMPK and ACC of L6 myocytes and HepG2 cells in a dose-dependent manner.