This study proposed a novel smoldering-driven reactor for plastic waste (PW) pyrolysis. The heat from self-sustaining smoldering was used to pyrolyze PW to produce oil and gas, a sustainable waste-to-energy approach. A multidimensional numerical model was developed to verify the feasibility and evaluate the performance of the proposed reactor. It was the first attempt to study the smoldering-driven pyrolysis of PW, including the melting process. The findings revealed that char smoldering could provide a stable propagating heat source for PW pyrolysis. The char concentration and air inlet velocity in the smoldering chamber could regulate the PW pyrolysis duration and product yields by controlling the peak temperature and heat propagation velocity. The pyrolysis product yields were controlled by PW content due to the change of velocity field in the pyrolysis chamber. The energy efficiency of PW pyrolysis was also evaluated under critical parameters.