Subzero-temperature frozen extraction technique which using acetonitrile as a solvent was applied to the extraction of pesticide such as Tribenuron,Primisulfuron,Hexaflumuron,Teflubenzuron,Triflumuron from flavored milk drinks.HPLC was used for the determination.The pesticide were separated by a reversed-phase C18 column and detected by Variable wavelength UV.The mobile phase was the mixture of methanol and water and the volume ratio was 73:27.Acetonitrile was used in extracting under 18 degrees below zero.Salt effect,frozen time and the volume ratio of extraction agent on the effect of extracting efficiency were studied.Under the optimal conditions,the linear regression equations of five pesticide was good and the correlation coefficient was more than 0.9994.The relative standard deviations were less than 2.333%.The recovery rates of the target analyte were between 92.3% and 98.7%.