The utility model relates to a seal casing for unbonded elastic wire resistance type strain meters, which consists of a section of stainless steel corrugated pipe. Through electron beam welding, laser beam welding or argon arc welding, both ends of the stainless steel corrugated pipe are respectively and hermetically welded with a steel connector base and a steel back base which are positioned at both ends of the unbonded elastic wire resistance type strain meter body. The seal casing which adopts the stainless steel corrugated pipe rather than a copper corrugated pipe and is welded with the steel connector base and the steel back base on both ends of the strain meter body through electron beam welding, laser beam welding or argon arc welding can save pipes and reduce cost, has high weld strength and a welded surface with a high finish degree, expands the application range of the unbonded elastic wire resistance type strain meters and prolongs the service life of the instrument.