Reinforced　concrete　is　deteriorated　by　chloride　attack　and　dry-wet　cycles　to　suffer　serious　durability　problems.　Reinforced　concrete　degradation　typically　occurs　in　two　distinct　stages:　initially　through　chloride　erosion,　followed　by　the　electrochemical　corrosion　of　rebars.　In　this　research,　COMSOL　Multiphysics　was　employed　to　model　how　various　crack　widths　impact　the　degradation　of　reinforced　concrete.　Findings　indicated　that　the　deterioration　process　of　reinforced　concrete　could　be　better　simulated　by　COMSOL　Multiphysics,　and　the　degradation　of　reinforced　concrete　was　significantly　influenced　by　crack　widths.　As　crack　widths　widen,　chloride　diffusion　accelerated,　leading　to　a　rise　in　the　corrosion　current　density　of　rebars.　Notably,　a　crack　width　increased　from　0.1　mm　to　0.4　mm　resulted　in　a　227.53%　higher　corrosion　current　density　in　rebars　after　150　days　of　exposure.　This　study　provides　a　theoretical　basis　for　predicting　reinforced　concrete　deterioration　in　the　future.　©　Published　under　licence　by　IOP　Publishing　Ltd.