Abstract: With the frequent and extensive use of acaricides, mites had developed increasing resistance to acaricides. It’s necessary to prepare new type of highly effective acaricide. A new acaricidal compound 3-(2,4,6-trimethyl-phenyl)-2-oxo-1-oxaspiro[4.4]non-3-en-4-yl butane-1-sulfonate (AC-118) was synthesized refer to the synthetic method of Spiromesifen. The toxicity of AC-118 against eggs and female adults of Tetranychus cinnabarinus were tested by leaf-dipping method and slide-dip method, respectively. The field control efficacy against Tetranychus vinnensis was also evaluated. The structure of AC-118 was confirmed by 1H NMR. The preliminary bioassay results showed that LC50 of AC-118 against eggs and female adults of Tetranychus cinnabarinus were 2.4 mg/L and 6.7 mg/L, respectively. 14 d after spraying in field, at the dosage of 2000 and 3000 times, 24% AC-118 SC provided 96.1% and 93.0% field control efficacy against Tetranychus cinnabarinus, respectively. 24% AC-118 ME provided 97.2% and 94.6% field control efficacy, respectively. At 3000 times, 24% Spiromesifen SC provided 93.9% field control efficacy. The control effect of AC-118 on Tetranychus cinnabarinus was equivalent to that of Spiromesifen. Compared with the traditional acaricides, AC-118 had the advantages of high bioactivity, rapid availability and long efficacy duration. Further development and research could be carried on to AC-118.