This study addresses the critical challenge of safe disposal and resource utilization of pig waste from intensive farming by investigating its pyrolysis behavior, product mechanisms, and heavy metal immobilization. The pyrolysis process was divided into four distinct stages, with kinetic parameters determined using the model-free FWO and KAS methods, ensuring accuracy without prior assumptions, complemented by the master plot method to elucidate reaction mechanisms. The optimal kinetic models identified as f(α)=4α