Strap for battery module, battery module comprising same, and jig for compressing strap

Disclosed is a strap, which compresses an outer surface of a battery module to prevent the battery module from being deformed by swelling of a battery cell, and the strap has a closed loop structure larger than an outer peripheral of the battery module, and at least a portion of the strap is folded at the closed loop to provide a welding portion at which the folded portions overlap each other when a predetermined compression is applied thereto.