Due to the presence of strong ligands such as ethylenediaminetetraacetic acid (EDTA), complexed heavy metals have high stability and complex morphology, and are difficult to be removed from wastewater by conventional water treatment methods such as adsorption, ion exchange, membrane separation, etc. Advanced oxidation technology(AOPs) is the first choice for the removal of heavy metals in complex state due to its strong oxidizing properties. It can not only decompose heavy metals, but also degrade the ligands. In the publishing research, the mechanisms of decomplexing using AOPs include the following aspects: (1) strong oxidation of free radicals, (2) gradual decarboxylation of ligands with EDTA, (3) self-catalysis of variable valence metal ions, (4) intermetallic substitution, (5) electrolysis, (6) multiple mechanisms combined, such as simultaneous decomplexation, mineralization of ligands, and recovery of heavy metals. In this review, from the perspective of different metals and ligands and their ability to complex, the research development of complexed heavy metal wastewater treatment are summarized, and the different complexation mechanisms based on AOPs are discussed. At the same time, the problems worthy of in-depth study are prospected.