As a typical municipal solid waste, the scrap tyres are difficult to clean due to their acid, alkali and biological resistance.The purpose of this paper is to study the pyrolysis mechanism of scrap tyres and the characteristics of pyrolysis oil components, so as to realize the resource utilization of the scrap tyres. The degradation characteristics of scrap tyres at different heating rates（5 ℃/min,10 ℃/min, 15 ℃/min and 20 ℃/min） were systematically investigated using thermogravimetric analysis（TGA）. The results show that the pyrolysis process of the scrap tyres mainly occurres in the temperature range of 200 ℃ to 500 ℃, and the mass loss curves（TG curves） and mass loss rate curves（DTG curves） gradually shift toward the higher temperature zone with the increase of heating rate.Three iso-conversion methods（Kissinger-Akahira-Sunose（KAS） model, Ozawa-Flynn-Wall（OFW） model and Friedman（FM） model）were used for kinetic analyses of the mass loss data, for which the apparent activation energies（Ea） are obtained to be in the ranges of 148 kJ/mol to 221 kJ/mol, 150 kJ/mol to 221 kJ/mol and 156 kJ/mol to 232 kJ/mol, respectively. Ea and pre-exponential factor（A）tend to increase and then decrease with the increase of the conversion rate. Then, the thermodynamic parameters（enthalpy change（ΔH）, Gibbs free energy change（ΔG） and entropy change（ΔS）） at different conversion rates were calculated by the OFW model. The calculation results indicate that ΔS and ΔH increase gradually with the increase of conversion rate until the conversion rate reached 0.9,and the opposite trend is observed for the change of the corresponding ΔG. In general, the effect of heating rate on the thermodynamic parameters is not obvious. In addition, the pyrolysis oil derived from the scrap tyre pyrolysis at 500 ℃ was analyzed by gas chromatography-mass spectrometry（GC-MS）, and the results exhibite that the content of D-limonene is up to 62.42%, which has a good utilization prospect. The results have a certain guiding significance for the resource utilization of scrap tyres and the optimization of pyrolysis technology.