The invention relates to an ultrahigh-manganese non-magnetic cast iron material and a preparation technology thereof. The ultrahigh-manganese non-magnetic cast iron material is composed of, by mass percentage, 25-30% of manganese, 0.8-2.0% of chromium, 0.02-0.04% of nickel, 0.01-0.02% of molybdenum, 0.5-3.0% of silicon, 1.8-2.6% of carbon, 0.4-0.7% of rare earth silicon, 0.03-0.1% of sulfur, 0.03-0.1% of phosphorus and the balance iron; the iron and waste steel are correspondingly weighed according to the element mass percent and are molten in a furnace at 1300 DEG C, then the manganese of the corresponding mass percent is added into the furnace and continuously heated to 1350 DEG C in the furnace, finally the other effective elements of the mass percent are added into the furnace and continuously heated to 1420 DEG C in the furnace, pouring is carried out for directly obtaining finished products, the products are free of magnetism, small in deformation, good in surface uniformity, stable and reliable, and the manufacturing cost is correspondingly lowered.