Novel composite modifier for austenitic manganese steel

The invention discloses a novel composite modifier for austenitic manganese steel, comprising rare earth alloy, ferrotitanium, calcium silicon and aluminum, wherein the dosage of the Re-containing rare earth alloy accounts for 0.20-0.25 percent of the weight of molten steel; the dosage of the ferrotitanium accounts for 0.02-0.03 percent of the weight of the molten steel; the dosage of the calciumsilicon accounts for 0.20-0.25 percent of the weight of the molten steel; and the dosage of the aluminum accounts for 0.15-0.20 percent of the weight of the molten steel. Treatment inside a furnace is carried out in the alloying adjustment stage for the composition of the molten steel after ferromanganese is added for the fine adjustment of the manganese content of the molten steel; one third of the rare earth alloy is added to a molten pool, and the aluminum is added before the tapping of the molten steel. Treatment outside the furnace is to add the calcium silicon, two thirds of the rare earth alloy and the ferrotit