Abstract: Plants have a long history as the main source and basic raw material of cosmetics. The efficacy and application of plant extracts in cosmetics are becoming more and more extensive. However, environmental pollution causes pesticide residue problems in plant extracts inevitably. "Cosmetics Safety Technical Specification (2015 Edition)" stipulates that a variety of pesticide ingredients are prohibited components of cosmetics. Moreover, the first cosmetics regulation EC 1223/2009 also clearly points out that pesticides such as aldrin and dieldrin are prohibited components in cosmetics. In this study, the 20 pesticide components selected as the main research content are all prohibited components specified in the "Cosmetics Safety Technical Specification (2015 Edition)". They have the high detection rate of daily detection and the same detection method. However, due to the lack of testing standards for pesticides in cosmetics at home and abroad, it is difficult to evaluate the pesticides in cosmetics on the domestic market. In particular, for cosmetics containing plant extracts that may contain pesticide residues, there is an urgent need to establish a simple, rapid, efficient and accurate pesticide residue detection and analysis method. Therefore, in order to improve the detection recovery rate, remove the interference of impurity components, reduce the mass spectrometry matrix effect and improve the detection sensitivity, gel permeation chromatography (GPC) purification methods were introduced into the sample pretreatment technology. A sensitive method for determination of 20 banned pesticides residues in cosmetics containing plant extracts by liquid chromatography tandem mass spectrometry（HPLC-MS/MS） was established. The target compounds were extracted with acetonitrile followed by GPC for cleanup step and concentrated to a constant volume, separated by high performance liquid chromatography, and then detected by electrospray tandem mass spectrometry qualitatively and quantitatively. The results showed that each target has good linearity in its own content ranges and the correlation coefficients are higher than 0.990. The limit of quantification (LOQ) of 20 pesticides is between 0.001-0.1 mg/kg, the average recovery at three spiked levels is 81.5%-116.2%, and the relative standard deviation (RSD) is 0.52%-9.42%. This method is simple, rapid and reliable, which can be used for determination of 20 pesticides in cosmetics containing plant extracts. This research can not only fill in the domestic and foreign gaps in the standard testing methods for pesticide residues in cosmetics, but also help actively respond to EU-related technical trade measures and guide companies to strengthen their own product quality management. It can provide technical support to improve the domestic and foreign cosmetics standard system, realize the monitoring of pesticide residues in cosmetics and ensure the quality and safety of cosmetics.