Sludge activated carbon (SAC_hdc) was prepared by high dehydration & carbonization equipment and used for adsorption phosphorus in wastewater. The sludge can be dehydrated until water content below 60%, then carbonized by the high dehydration & carbonization equipment. The SAC_hdc used as absorbent in phosphorus of wastewater treatment. The experimental results showed that the adsorption capacity of phosphorus could reach 4.598 mg/g, and adsorption rate was above 91%, the pseudo-second-order kinetic equation and Freundlich isotherm model could describe the phosphorus adsorption process of SAC_hdc. SAC_hdc prepared and used as absorbent realized the sludge harmless and resource utilization.