Abstract:The merits and demerits of many kinds of displacement measuring technique adopted mainly at present are discussed. The principles and methods of digital close-range photogrammetry are introduced. The error of this method is analysed and it is firstly applied to measure the displacement in sectional model test. This technique is of many advantages,such as contactless,simple apparatus,easy operation,low demand of environment,providing directly the elements of inner-azimuth,no error of negative pressure to plane,high automation and high precision. The test results indicate that the displacement field measured by this technique is of evident regularity and its measuring results fit well with the phenomenon occurring in the process of test. The difference between close-range photogrammetry and dial gauge is within 30 percent.