Uniaxial tension device and testing method thereof

The invention relates to the field of geotechnical engineering testing equipment, in particular to a uniaxial tension device and a testing method thereof. The uniaxial tension device comprises a base, wherein a reaction frame is mounted on the base; a first fixed seat is mounted on the base and is connected with a lifting device in the base; a second fixed seat facing to the first fixed seat is arranged on the reaction frame; the second fixed seat is connected with the reaction frame through a spring; a length measuring instrument is arranged between the second fixed seat and the reaction frame. By using a calibrated spring, the strain of soil samples or test samples when being destructed is measured through the length measuring instrument, and then a tension strength value of the soil samples is obtained through Hooke Law. The tension of the test samples is obtained through back calculation by using the strain of the spring. Since the device changes displacement by using a lower portion, the influence of the dead weight of the test samples on measurement results is effectively reduced. Compared with the prior art, the accuracy is higher.