The　main　factors　affecting　the　durability　of　a　reinforced　concrete　bridge　are　the　fatigue　effect　brought　on　by　continuous　traffic　loads　and　chloride　ion　erosion,　but　studies　on　how　these　two　factors　interact　have　been　scarce.　As　a　result,　concrete　structure　durability　analyses　need　to　be　more　thorough　and　accurate.　The　fatigue　model　from　continuum　damage　mechanics　is　used　to　determine　the　equivalent　stress　range　of　traffic　loads,　and　poroelasticity　is　used　to　establish　the　link　between　volumetric　strain　and　porosity.　Following　a　change　in　the　porosity＇s　function,　the　chlorine　ion　diffusion　coefficient　is　covered.　Finally,　a　proposed　coupling　analysis　method　that　takes　many　physics　into　account　is　presented.　This　method　takes　into　account　fatigue　stress,　body　strain,　porosity,　chlorine　ion　diffusion　coefficient,　and　corrosion　rate.　The　multiphysics　finite　element　program　and　the　associated　theoretical　equations　can　be　used　to　simulate　the　chloride　ion　diffusion,　erosion　states,　corrosion　rate,　and　bearing　capacity　of　the　main　sections　in　various　stages.　As　a　result,　the　reinforced　concrete　bridge＇s　evolutionary　durability　can　be　fully　attained.　Fatigue　loading　can　accelerate　corrosion　of　reinforcement　and　chloride　ion　diffusion,　which　accelerates　the　loss　of　a　bridge＇s　flexural　strength.　The　method　described　in　this　paper　can　calculate　the　flexural　load　capacity,　erosion　state,　time-varying　rust　rate,　and　chloride　ion　diffusion　effect　of　the　main　bridge　sections　at　various　times,　which　can　show　the　detailed　evolution　of　reinforced　concrete　bridge　durability　and　offer　useful　theoretical　and　technical　support　for　decisions　about　bridge　durability　assessment　and　maintenance