Rock-soil body triaxial test strain measurement device based on digital image technology

The invention discloses a rock-soil body triaxial test strain measuring device based on a digital image technology, which comprises a sample (4), a pressure chamber (5), a confining pressure tank (6), a sample base (7), a high-frequency camera (10), a numerical control device and a computer, the pressure chamber is formed on the inner circumference of the confining pressure tank, the sample is arranged in the pressure chamber and is arranged on the sample base, the confining pressure tank comprises an inner wall (61) and an outer wall, and the outer wall is arranged on the outer wall. The device is characterized in that a high-frequency camera is arranged on the peripheral surface of the inner wall, a first track (12) and second tracks (13) are arranged on the peripheral surface of the inner wall, the first track is a circumferential annular track, the second tracks are axial/longitudinal linear tracks, the number of the second tracks is multiple, the second tracks are connected with the first track, and the