The　SO4•–　radical　based　advanced　oxidation　process　(SR-AOP)　is　the　effective　remediation　strategy　for　addressing　the　concern　of　severe　pollution　risk　caused　by　recalcitrant　pollutants.　In　this　study,　we　report　the　visible-light-driven　photocatalytic　activation　(VL-PCA)　of　PMS　by　using　K+-induced　structure　remodeling　high　crystallinity　of　(KPCN).　The　degradation　of　sulfamethoxazole　(SMX)　by　KPCN+PMS+VL　system　(the　corresponding　kinetic　constant　is　0.1452　min–1)　was　enhanced　remarkably　compared　with　PCN+PMS+VL　system　(0.0263　min–1).　•O2–,　1O2,　•OH　and　SO4•–　radicals　were　the　dominant　reactive　species　for　the　enhanced　decomposition　of　SMX,　evidently　demonstrated　by　reactive　species　scavenger　and　electron　paramagnetic　resonance　(EPR)　experiments.　The　KPCN　crystalline　semiconductors　maintain　the　properties　of　long-range　atomic　order　configuration　and　nonlinear　optical　(NLO)　response　of　pristine　PCN.　The　unique　NLO　effects　of　KPCN　enable　it　to　produce　more　photogenerated　carriers　and　minimize　the　electron-hole　pair　recombination,　which　exhibit　superior　VL-PCA　performance　of　PMS　toward　SMX　degradation.　This　study　gives　a　proof-in-concept　demonstration　of　the　increased　activity　of　the　C3N4-based　PMS　photocatalytic-activator　by　regulating　the　disordered　structure　and　phase　defects　of　PCN,　shedding　light　on　the　development　of　highly　efficient　VL-PCA　catalysts　based　on　carbon　nitride.　©　2022　Elsevier　B.V.