The invention belongs to the field of insecticides and relates to a synergistic miticidal composition containing two active ingredients A and B, wherein the ratio of the parts by weight of the ingredient A and the ingredient B is (1:100)-(100:1); and the active ingredient A is selected from a compound I shown by a structural formula in the specification, the active ingredient B is selected from an insecticide/acaricide, and the structure of the active ingredient A is as shown in the specification. The composition provided by the invention has the advantages of obvious synergistic effect, capability of delaying resistance and the like, and can be used for controlling various harmful insects.