In order to solve the problem of environmental pollution and fossil resource consumption caused by nylon 66(PA66) waste, PA66 based carbon dots(66CDs) were prepared by solvothermal method with PA66 and phytic acid(IP6) as precursors and acetic acid as solvent. The structure, properties and application of PA66 were investigated. The results showed that the optimum conditions for the preparation of 66CDs were as follows:1.6 g PA66,1.1 g IP6 and 20 mL CH3COOH were added to 50 mL para polyphenol hydrothermal reactor and placed in 260 ℃ blast drying oven for 36 h. The fluorescence of the prepared 66CDs was wavelength independent, and the best excitation wavelength and the best emission wavelength were 360 nm and 490 nm, respectively. In terms of structure, 66CDs is spherical with an average particle size of 4.00 nm, and the surface contains carboxyl, hydroxyl, amino and other functional groups. In addition, the fluorescence intensity of 66CDs is not affected by common metal ions, and the anti-interference ability is outstanding, which can be used for fluorescence anti-counterfeiting and fingerprint recognition.