Insufficient　examination　of　safety　risk　propagation　within　complex　construction　projects　(CCPs)　leads　to　defective　risk　responses.　This　study　attempts　to　exemplify　metro　deep　foundation　pit　projects　to　investigate　the　mechanisms　underlying　this　propagation.　The　interaction　network　of　safety　risk　factors　is　constructed　utilizing　association　rule　mining　and　link　prediction.　A　modified　susceptible-infectious-recovered　(SIR)　model　is　used　to　simulate　and　analyze　risk　propagation　within　the　network.　The　results　highlight　distinct　risk　propagation　dynamics　triggered　by　various　initial　hazardous/controlled　factors.　Risk　factors　from　the　owner　or　social　environment　are　critical　in　initiating　and　controlling　propagation,　while　those　from　the　survey　unit,　designer,　supervision　unit,　monitoring　unit,　working　environment,　or　the　contractor＇s　organizational　and　managerial　aspects　have　moderate　effects.　The　contractor-related　unsafe　behaviors,　mechanical,　material,　or　structural　factors,　and　natural　environmental　factors　exhibit　relatively　limited　impact.　The　ultimate　risk　level　is　contingent　upon　initial　hazardous　and　controlled　factors,　with　the　risk　controllability　solely　determined　by　the　latter.　It　is　recommended　that　the　focus　of　safety　management　be　broadened　from　contractors　to　owners　and　the　social　environment,　and　from　isolated　risk　responses　to　risk　network　management.　This　study　may　deepen　managers’　understanding　of　the　sources　of　safety　risk　within　CCPs,　thereby　promoting　project　success.　©　2025　Elsevier　Ltd