The invention discloses a low-nickel nitrogen-containing austenitic stainless steel non-consumable electrode gas shielded welding wire and a preparation method thereof. The invention belongs to the technical field of welding material preparation and welding machining processes thereof. The low-nickel nitrogen-containing austenitic stainless steel non-consumable electrode gas shielded welding wireand the preparation method solve the technical problems that when an existing austenitic stainless steel welding wire is used for conducting non-consumable electrode gas shielded welding on low-nickelnitrogen-containing austenitic stainless steel, nitrogen loss, air holes, hot cracks in a weld joint area and nitride precipitation in a heat affected zone are prone to being generated in a welded joint, and consequently pitting corrosion is caused. The low-nickel nitrogen-containing austenitic stainless steel non-consumable electrode gas shielded welding wire comprises the following chemical components including, by weight, 0.03% to 0.08% of C, 0.30% to 0.65% of Si, 6.50% to 8.50% of Mn, less than or equal to 0.05% of P, less than or equal to 0.01% of S, 17.50% to 18.50% of Cr, 2.20% to 2.90% of Ni, 0.03% to 0.10% of Mo, 1.00% to 2.00% of Cu, 0.15% to 0.35% of N, less than or equal to 0.05% of Co, less than or equal to 0.05% of the sum of Nb, Ti and V and the balance iron. The method comprises the steps of smelting, wire rod hot rolling and welding wire drawing, and finally the welding wire is obtained. According to the low-nickel nitrogen-containing austenitic stainless steel non-consumable electrode gas shielded welding wire and the preparation method, solid solution nitrogen is used for partially replacing nickel, and grain refinement can be promoted while nitrogen is effectively subjected to solid solution strengthening.