A　synergistic　photocatalytic　system　based　on　Fe-based　perovskite　with　persulfate　was　constructed　for　alkali　lignin　(AL)　degradation　in　pulp　and　paper　wastewater.　The　degradation　performance　and　mechanism　on　AL　were　carried　out　under　ambient　temperature　and　pressure,　accompanied　by　visible　light　irradiation.　The　results　showed　that　the　synergistic　photocatalytic　system　exhibited　much　better　performance　on　AL　degradation　than　the　single　catalytic　system.　The　degradation　efficiency　reached　73.5%　under　the　optimal　conditions　and　was　constant　at　around　65%　over　the　pH　range　from　2　to　8.　A　significant　escalation　of　the　AL　degradation　was　observed　at　pH　10,　reaching　80.1%.　The　photogenerated　holes,　1O2　and　SO4−·,　generated　by　the　system　were　involved　in　the　degradation,　and　the　holes　played　a　dominant　role.　During　the　degradation　process,　the　efficient　promotion　of　cleavage　events　in　lignin　methoxy,　β-O-4　bond,　and　benzene　ring　was　observed.　Consequently,　the　depolymerization　process　led　to　the　generation　of　high-value　compounds,　namely　p-hydroxybenzaldehyde　and　vanillin.　Remarkably,　the　yields　of　the　high-value　compounds　in　the　synergistic　photocatalytic　system　were　five　times　larger　than　those　in　the　control.　This　study　offered　a　viable　method　to　activate　persulfate　for　alkali　lignin　degradation　and　to　achieve　a　mutually　beneficial　strategy　for　wastewater　treatment　and　recycling.　©　The　Author(s),　under　exclusive　licence　to　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2024.