The composition of waste circuit boardWaste circuit boards is complex but there are more valuable elements to recycle. The E-pH diagramE-pH diagrams was plotted based on the thermodynamicThermodynamics data manually. The thermodynamicsThermodynamics of leaching is investigated for the chlorination treatment system of waste circuit boardsWaste circuit boards. The results indicated that a stabilization zone for each metal-chlorine complexChlorine complexes occurs when the pH < 1.98 and E > 1.39V. The conditions can be maintained for better leaching of each metal during chlorinated leaching. Meanwhile, the relationship between the effect of [Cl]T change on the concentration of each ion and the concentration fraction φ of each metal-chlorine complexChlorine complexes versus [Cl]T was drawn. The results revealed that the concentration of each free metal ion decreased continuously with the increase of [Cl]T.