A series of Sr-doped BiFeO3 perovskites(Bi1-xSrxFeO3,BSFO)fabricated via sol-gel method was applied as peroxydisulfate(PDS)activator for ciprofloxacin(CIP)degradation.Various technologies were used to characterize the morphology and physicochemical features of prepared BSFO samples and the results indicated that Sr was successfully inserted into the perovskites lattice.The catalytic performance of BiFeO3 was significantly boosted by strontium doping.Specifically,Bi0.9Sr0.1FeO3(0.1BSFO)exhibited the highest catalytic per-formance for PDS activation to remove CIP,where 95％of CIP(10 mg/L)could be degraded with the addition of 1 g/L 0.1BSFO and 1 mmol/L PDS within 60 min.Moreover,0.1BSFO dis-played high reusability and stability with lower metal leaching.Weak acidic condition was preferred to neutral and alkaline conditions in 0.1BSFO/PDS system.The boosted catalytic performance can be interpreted as the lower oxidation state of Fe and the existence of afflu-ent oxygen vacancies generated by Sr doping,that induced the formation of singlet oxygen(1O2)which was confirmed as the dominant reactive species by radical scavenging stud-ies and electron spin resonance(ESR)tests.The catalytic oxidation mechanism related to major 102 and minor free radicals was proposed.Current study opens a new avenue to de-velop effective A-site modified perovskite and expands their application for PDS activation in wastewater remediation.