Polyaluminum chloride (PAC) is commonly used as a flocculant in wastewater treatment plants to aid in the removal of phosphorus (P) from wastewater. As a result, the P element present in PAC-treated sludge is predominantly in the form of Al-P. This study proposes the use of alkaline anion exchange resin (AAER) as a pretreatment method for PAC-treated sludge to enhance P extraction and achieve cleaner P recovery from this type of sludge. The findings of the study indicate that the optimal concentration of AAER is 12 g/g TS, resulting in a P extraction efficiency of 67.2 %. This represents a 26.5 % increase compared to alkali treatment at the same pH (pH = 12.23). Stepwise extraction analysis and molecular dynamics simulations suggest that during AAER treatment, Al(OH)3 is converted into dissolved [Al(OH)4]−. These species then agglomerate with PO43− and subsequently get adsorbed by the N(CH3)+ groups on the AAER. Furthermore, even after undergoing five regeneration cycles, the AAER still exhibits a significant adsorption capacity for P. Ultimately, high-purity Ca10(PO4)6(OH)2 is obtained as the final product with a recovery rate of 90.5 %. Meanwhile, the Al extracted by AAER can be reused as a feedstock for polymerized aluminum chloride. This demonstrates that AAER extraction is a promising and efficient waste management strategy for the clean recovery of P and Al from PAC sludge.