This study presented new insights into the sustainable conversion of total petroleum hydrocarbon (TPHC) into polyhydroxyalkanoates (PHAs) using wetland microbial fuel cells (WMFCs). The main innovations included the following two points: (1) The integration of bioelectricity generation with efficient PHA production further underscored the potential of electroactive biofilms as a sustainable platform for simultaneous TPHC biotransformation, bioelectricity recovery and PHA production. (2) The interactive dynamics of PHAs, metabolites, extracellular polymeric substances (EPS) and microorganisms during the formation and stabilization of electroactive biofilms provided novel insights into microbial strategies for carbon utilization. As the electroactive biofilm formed and stabilized, the current density enhanced significantly from 0 to 101 mA m