To　reveal　the　evolution　characteristics　and　influencing　factors　of　atmospheric　PM2.5-O3　complex　pollution　in　Xingtai　City,　this　study,　based　on　the　meteorological　elements　and　pollutant　concentration　data　provided　by　the　online　monitoring　platform,　deployed　the　KZ　filtering　method　to　decompose　the　original　concentration　sequences　of　PM2.5　and　O3　in　Xingtai　City,　and　combined　the　multiple　stepwise　regression　method　to　quantitatively　identify　the　contribution　of　source　emissions　and　meteorological　factors　to　pollutant　concentration　in　long-term　component.　Meanwhile,　Random　Forest　method　was　used　to　qualitatively　explore　the　effects　of　specific　source　emissions　and　meteorological　factors　on　the　original　concentration　series　of　PM2.5　and　O3　in　Xingtai　City.　The　results　showed　that　the　long-term　component　of　PM2.5　concentration　in　Xingtai　City　showed　a　significant　downward　trend,　however,　short-term　component　was　major　contributor　to　PM2.5　concentration.　The　long-term　component　of　O3　concentration　showed　an　increasing　trend,　and　the　seasonal　component　was　main　contributor　to　O3　concentration.　The　contribution　ratio　of　source　emissions　to　meteorological　factors　in　the　long-term　component　concentrations　of　PM2.5　was　about　5:1,　and　that　for　O3　was　close　to　3.5:1.　The　source　emission　processes　were　the　main　cause　of　long-term　atmospheric　PM2.5-O3　complex　pollution　in　Xingtai　City.　Relative　humidity　(RH)　presented　a　significant　influence　on　the　original　concentration　series　of　PM2.5　in　Xingtai　City,　followed　by　industrial　source　emission　and　vehicle　exhaust　emission.　The　three　factors　effectively　affecting　the　original　O3　concentration　sequences　were　the　short-wave　radiation　intensity　(SR),　temperature　(T)　and　vehicle　exhaust　emission.　©　2024　Chinese　Society　for　Environmental　Sciences.　All　rights　reserved.