Abstract: The pressure-bearing part of seawater desalination pump is made of 2507 super duplex stainless steel. the manual arc welding was used with E2594-16 welding rods,welding heat input was controlled at 1 800 J/cm² and interlayer-temperature was limited below 100 ℃. After the solid solution treatment at 1 080 ℃,defects in casts were fixed. Based on the studies,the optimized welding repairing process parameters for 2507 super duplex stainless steel casting were obtained,which can provide a guidance for the fabrication of 2507 super duplex stainless steel casting used in Seawater desalination pumps.