Abstract: The polyolefin compounds with halogen-free flame retardants were prepared by a melt blending method, and the thermal-oxidative aging and thermal cracking properties, oxidation induction time of the resulting flame-retardant compounds were characterized by means of oven heating, universal testing machine and differential scanning calorimetry. The results indicated that, when different halogen-free flame retardants were incorporated, the flame-retardant polyolefin compounds presented the improved thermal oxidative aging performance by an order of zinc borate>Mg(OH)2>Sb2O3>melamine cyanurate>Al(OH)3>phosphate>CaCO3. The smaller the particle size of halogen-free flame retardants, the poorer the thermal oxidative aging performance. In addition, the surface treatment of halogen-free flame retardants improved the thermal oxidative aging performance of flame-retardant polyolefin compounds.