The work aims to extract four kinds of composite plastics with ethanol, methanol, n-hexane, acetone and tetrahydrofuran as solvents, to obtain the best extraction process, including the extraction solvent, extraction time, extraction temperature and dosage of extraction solvent through analysis, and to detect the content of pollutants in composite plastics. The samples were extracted with ultrasonic technology, and the content of pollutants in four kinds of plastic products was analyzed with gas chromatography. The surface morphology of the plastic products before and after ultrasonic extraction was observed by scanning electron microscope. The surface morphology of the plastic was changed after being extracted with 4 kinds of solvents. But the effect of n-hexane and acetone on the plastic surface was obvious, and they both led to a swelling and whitish plastic surface. The peak area of the standard sample was measured in combination with gas chromatography and the results showed that: the solubility of standard samples was the best when the solvent was n-hexane, so the best extraction solvent was n-hexane. In the process of extracting plastic products with n-hexane, as the temperature rose, the content of the extracted pollutants was increased. But when the temperature reached 50 ℃, the increase was not obvious, so the optimum extraction temperature was 50 ℃. Under the optimum extraction temperature, the best extraction amount of n-hexane was 20 mL. Finally, the content of pollutants in plastic products was measured. It was concluded that a certain amount of pollutants existed in four kinds of composite plastics. The content range of BHT was 0.0016%~0.11%, higher than the national standard, and the pollutants exceeded the standard. The efficiency will be the highest when the extraction lasts for 20 min with 20 mL n-hexane at 50 ℃. The data measured with gas chromatographic show that a certain amount of pollutants exist in all the four kinds of composite plastics.