Industrial by-products FeSO4·7H2O is taken as raw material, concentrated nitric acid as strong oxidant and aluminum sulfate as additive to produce poly aluminum ferric sulfate(PAFS）flocculants, which is applied to the removal of organic humic acid. The study includes the reaction temperature, reaction time, Al/Fe molar ratio and basicity(OH/Fe). Infrared spectroscopy and scattering electron are used to characterize the structure of the PAFS. The results show that the product have the best coagulation effect when reaction temperature, reaction time, Al/Fe molar ratio and basicity(OH/Fe）are 60～80℃, 30～50 min, 1∶9 and 0.3 respectively. Infrared spectroscopy analysis shows the products structure and scattering electrons analysis suggests a large surface area and a strong condensed state for PAFS. The removal rate of humic acid is 94.72% when the dosage of PAFS is 3.36 mg /L, pH value is 7, rapid stirring speed is 350 rpm, fast mixing time is 2.0 min, the slow stirring speed is 40 rpm and slow stirring time is 12 min.