The identification of recycled materials in common food contact materials of polypropylene (PP) products was researched. Firstly, Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC) and thermogravimetric analyzer(TGA) were used to analyze the composition, structure and thermal properties of the samples，from which abnormal data were obtained. Then field emission scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS) were utilized to accurately analyze the micro morphology and element composition of the samples. Furthermore, the contents and migration of harmful substances such as fluorescent brightener, heavy metal and plasticizer in the samples selected were examined. The results showed that sample 1# was made of PP, but its thermal properties were poor. There were no other impurities in the matrix of sample 1#, in which harmful substances of heavy metals and fluorescent brightener were not detected. The testing results of great concern of phthalate plasticizers also met the standard.