In this study, wood plastic composites (WPC) were made using waste automobile bumpers (WAB) and sugarcane skin flour (SSF) as matrix and fibres, respectively. A novel KH550/TCA201 composite coupling agent was applied to modify the composites. Then, the composites were analysed by FTIR, TG-MS, GC-MS and SEM-EDS after being pyrolyzed in a thermogravimetric analyser and a tubular fixed bed. The results show that the mechanical strength of the composite modified by the KH550/TCA201 composite coupling agent is higher than that of the composite modified by a single coupling agent. When KH550/TCA201 is 2% with KH550:TCA201 = 1:1, the tensile, flexural and impact strength of the WPC composites reaches a maximum. In the pyrolysis of WPC, a large amount of alkanes, olefins, aromatics and a small amount of CO2 were produced from 380 degrees C to 500 degrees C. During the WPC pyrolysis process, the release of HF and HBr is higher than that of WAB, whereas the release of HCl is less than that of WAB. In the pyrolysis oil, the main fluoride production occurs at 400-600 degrees C and reaches a maximum at 500 degrees C. Meanwhile, in the fast pyrolysis oil, the content of organic fluoride is 6 times higher compared with the slow pyrolysis oil. For the solid residue, the content of F, CI, Br and other pollutants increased with an increase in temperature. Specifically, the chlorine content was higher at slow pyrolysis than at fast pyrolysis. Therefore, from a controllable and environmental standpoint, slow pyrolysis should be adopted in order to increase the content of the contaminated halogen elements in the solid residue. (C) 2019 Published by Elsevier B.V.