Ploy-high-ferric-silicic coagulant was prepared using the fly ash extract and potassium ferrate. The flocculation process of treatment lead wastewater by this coagulant with various Si/FeO42- ratios and salt-basicity at different pH and dosage were studied by jar test. The results showed that color, turbidity and Pb2+ removal efficiency are excellent and treatment effects are stable in treatment lead wastewater, especially the removal of Pb2+ has been up to 96% more. The comparison on coagulation between poly-high-ferric-silicic and other coagulants, the poly-high-ferric-silicic dosage is low and adapt to a wide PH. Therefore, by comparison, the poly-high-ferric-silicic is a superior coagulant in lead wastewater treatment.