To　explore　the　fatigue　performance　of　3D　printed　concrete,　216　3D　printed　specimens　were　subjected　to　bending　fatigue　tests,　and　the　effects　of　different　volume　ratios　ρf　and　lengths　lf　of　steel　fibers　on　the　bending　tensile　strength　and　fatigue　performance　of　the　components　were　analyzed.　Based　on　the　two-parameter　Weibull　distribution　theory,　fatigue　life　calculation　formulas　were　derived　for　different　failure　probabilities.　The　fatigue　equations　for　different　failure　probabilities　were　proposed,　and　the　influence　of　steel　fibers　parameters　on　the　fatigue　performance　of　components　was　further　analyzed.　The　research　results　show　that　the　fatigue　failure　process　in　3D　printed　concrete　components　involves　the　crack　resistance　effect　of　steel　fibers.　During　the　process　of　crack　generation,　expansion,　contraction,　re-expansion,　and　re-contraction,　the　width,　length,　and　depth　of　the　crack　constantly　change.　Microscopically,　it　involves　continuous　deterioration　of　the　material＇s　internal　structure.　The　incorporation　of　steel　fibers　into　3D　printed　specimens　can　effectively　prevent　the　generation　and　expansion　of　transverse　cracks,　significantly　improving　the　flexural　tensile　strength,　crack　resistance　and　shrinkage　limiting　ability,　and　fatigue　resistance　of　concrete　components　and　transitioning　their　failure　mode　from　sudden　brittle　failure　to　ductile　plastic　failure.　The　parameter　ρf　lf/df　of　steel　fiber　is　an　important　factor　affecting　the　flexural　tensile　strength　and　fatigue　resistance　of　components.　The　fatigue　number　of　the　component　increased　by　252%　when　the　ρf　lf/df　increased　from　0　to　0.60　under　the　same　stress　ratio　S=0.65,　and　the　stress　ratio　increased　by　9.15%　when　the　ρf　lf/df　increases　from　0　to　0.60　under　the　same　fatigue　number　N=106.　The　research　results　are　of　great　significance　for　further　promoting　the　applications　of　3D　printing　technology　in　the　transportation　field,　promoting　industry　intelligence,　and　industrial　development.　©　2024,　Central　South　University　Press.　All　rights　reserved.