Welding wire for welding casing and preparation method and application thereof

The invention provides a welding wire for welding a casing and a preparation method and application thereof, and belongs to the field of welding materials. The welding wire comprises the following elements: 0.03-0.06wt% of C, 15-16wt% of Cr, 14-16wt% of Mo, not greater than 1wt% of Fe, not greater than 0.5wt% of Si, 1-2wt% of Mn, not greater than 0.015wt% of S, not greater than 0.015wt% of P, andthe balance Ni; and the welding wire comprises the following gas elements: not greater than 0.0017wt% of O, not greater than 0.0018wt% of N, and not greater than 0.0002wt% of H. The preparation methodof the welding wire comprises the steps of alloy smelting, forging, hot rolling and cold drawing. The prepared welding wire can improve the welding firmness of alloys with high contents of aluminum and titanium, is not easy to generate welding cracks, greatly improves the thermal cracking resistance of welding lines, can resist high-temperature welding of 900 DEG C, and is suitable for welding ofage-hardening alloy casing