In recent years, with the increasing of water treatment, the production of coagulated sludge has a sharp rise. So, the realization of coagulated sludge resource utilization is necessary. In this research, the coagulated sludge treated by carbonization at high temperature and polymerized ferrous sulfate (PFS) were added together to remove Fe(CN)63? pollutants. And the mechanism of coagulation was further studied. The structure of the coagulated sludge materials was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetic hysteresis curve. The pollutant of Fe(CN)63? coagulated by PFS and coagulated sludge was analyzed by the removal rate, particle size and shape. The results showed that the sludge materials contained a large amount of carbon and it had some functional groups like carboxyl on the surface. Iron and vanadium oxides which had complexation ability were formed on the surface carbonized sludge materials. The crystallinity and grain size of the coagulated sludge were more ordered and more uniform by carbonization at high temperature which could benefit to the growth of flocs in the process of coagulation. The removal of Fe(CN)63? increased by adding coagulated sludge. Especially, the removal of Fe(CN)63? increased to 99.45% by adding the sludge which was carbonized at 700℃ with PFS:RW700=1:1.43. By the analysis of particle size and shape, the coagulated sludge was beneficial to the enhancement of pollutants during coagulation process. By optimizing the ratio of sludge material to PFS, the removal of Fe(CN)63? pollutant was also close to 100% by reducing the dosage of PFS. Compared with the other coagulants, the cost of water treatment decreased. This study provided theoretical and technical basis for the resource recycling of coagulated sludge. This new type of sludge resource utilization had promising application in the field of cyanide removal.