In　this　paper,　with　the　increasing　requirement　on　the　abatement　of　SO2　emission　in　flue　gas,　cyber-physical　system　(CPS)　is　introduced　into　the　limestone　wet　flue　gas　desulfurization　process.　The　slurry　pH　value,　a　key　factor　affecting　the　flue　gas　desulfurization　rate,　is　analyzed　and　controlled　in　the　context　of　cyber　physical　system　on　the　basis　of　four　stages,　namely,　state　perception,　real-time　analysis,　scientific　decision　and　precise　execution.　The　simulation　result　reveals　that　the　slurry　pH　value　can　be　controlled　effectively　both　in　accuracy　and　timeliness　in　the　context　of　CPS.　Meanwhile,　the　on-site　data　provides　a　compelling　evidence　that　pH　control　in　the　context　of　CPS　outperforms　that　in　traditional　wet　flue　gas　desulfurization　system.　©　2020　IEEE.