Abstract: The production of high-strength and high-toughness spring steel is a key component in the lightweight development trend of the automotive industry.To address the issue of significant macrosegregation control in the continuous casting of 55 SiCrA spring steel,this study develops a coupled multi-physics numerical model integrating "flow-heat transfer-electromagnetic field-solute transport" for the actual industrial continuous casting process of280 mm×280 mm spring steel blooms.The accuracy of the solute field predicted by the model was verified through industrial-scale sampling.Furthermore,the effects of submerged entry nozzle（SEN）structure,casting superheat,and mold electromagnetic stirring（M-EMS）on solute transport during continuous casting were systematically investigated.The results indicate that the SEN structure significantly influences molten steel flow and solute transport behavior.The use of a four-port nozzle reduces the severity of negative segregation under bloom surface and eliminates its asymmetry.Increasing the superheat prolongs solute precipitation and transport at the solidification front,thereby intensifying negative segregation under bloom surface.M-EMS enhances molten steel turbulence and accelerates heat dissipation,which helps mitigate the original negative segregation;however,it also increases the scouring effect at the solidification front,potentially leading to the formation of a secondary negative segregation band within the mushy zone.