A strain measurement device includes a strain gauge, a holding device, a transverse strain recorder, and a data processing device. The strain gauge includes at least one first and at least one second layers of carbon nanotube films, each layer of carbon nanotube films having a plurality of carbon nanotubes. The carbon nanotubes in at least one first layer of carbon nanotube film align along a first direction. The carbon nanotubes in at least one second layer of carbon nanotube film align along a second direction. The holding device is used to fasten a specimen and the strain gauge. The transverse strain recorder is used to record a transverse strain of the strain gauge. The data processing device is used to calculate an axial strain of the strain gauge.