Abstract: This study focused on optimization of immobilization conditions of phospholipase A1, and then the immobilized PLA1 was used in soybean oil degumming process.Phospholipase A1 was immobilized by Fe3O4/SiOx- g- P ( GMA) . The obtained magnetic immobilized PLA1 was used for soybean oil degumming, then, the regeneration of magnetic immobilized PLA1 was studied.The results showed that the optimal immobilized conditions were: the enzyme dosage was 20 mL, pH was 6.0, the reaction time was 5h, and the relative activity of magnetic immobilized PLA1 was the highest under the optimal conditions. The optimal conditions of degumming were: the reaction time was 6h, the reaction temperature was 55 ℃, the dosage of magnetic immobilized PLA1 was 0.12 g /kg, initial pH of oil phase was 6.0.The residual phosphorus content of degummed soy oil was decreased to 12.5mg /kg under the optimum conditions. The phosphorus could be removed effectively. Then the regenerated magnetic immobilized phospholipase A1 was used in soybean oil degumming, the used time of the magnetic immobilized phospholipase A1 was prolonged, and the cost of enzymatic degumming of soybean oil was reduced.