In order to explore the best adsorbent and new way of removing phosphorus, this trial uses coal fly ash with PFS and alkali modified coal fly ash to deal with phosphorus in Secondary Effluent. The results: using the coal fly ash with PFS to deal with the model wastewater of 3mg/L, the removing rate can reach 72%. The combination of coal fly ash and PFS can make adsorption and coagulation express synergistic effect, and strengthen the Coagulation Effect. Using the NaOH modified coal fly ash to deal with phosphorus in Secondary Effluent, when dosage is 8g and stirs for 5min in 30r/min, the removing rate can reach 90%. After modified, coal fly ash expresses the adsorption, at the same time coal fly ash and phosphoric acid root ion settles, and strengths the treatment effect. Comparative analysis of the two methods, the NaOH modified coal fly ash can remove phosphorus effective and realize spate separation. This method can reduce the cost, and the metod is easy. It is worth to extensive application.