Abstract: With the increasingly strictness of the pollutants emission limits, people have paid more and more attention to the polycyclic aromatic hydrocarbons (PAHs) formation during combustion process. Based on the analysis of PAHs formation mechanisms, including 101 gas species and 504 elemental reactions, the kinetic simulation of PAHs formation during gas phase combustion of the typical volatile matter from plastic pyrolysis using elementary reaction mechanisms was carried out in this work. rB is defined as the ratio of actual fuel/air to stoichiometric fuel/air. The simulation results show that with the increase of rB in combustion at same reaction temperature, the combustion becomes incomplete and the peak value of PAHs mole fraction goes up. Under the same value of rB in combustion, increasing combustion temperature can reduce the incomplete reaction, at the same time, the peak of PAHs appears early, and the peak value increases. In addition, the simulation results of three typical wastes at same conditions of rB and combustion reaction temperature show that the mole fractions of PAHs in the flue gas of paper combustion are less than those of plastic and fabric, and the yields of PAHs for plastic and fabric are almost the same.