Abstract: End friction effects in triaxial tests can lead to overestimation of soil strength. This study investigated the influence of end friction on different regions of the soil specimen (divided into 1/4, 2/4, 3/4, top, and bottom sections based on coded points) using photogrammetry. An end restraint coefficient (β) was introduced to quantitatively analyze the extent of friction effects. In addition, discrete element software PFC was used to simulate and validate the behavior of the specimen under various end restraint conditions.The results show that: (1)The 1/4 region at the center of the specimen is minimally affected by end restraint and exhibits more uniform deformation, which effectively represents the overall strength of the specimen. (2)The results of PFC simulations under unconstrained end conditions align with the photogrammetric measurements. (3)The end restraint coefficient (β) effectively reduces the interference of end friction effects, providing more accurate deformation and reliable strength data for the soil specimen.The proposed method, which uses localized deformation data to mitigate end friction effects, offers technical support for improving the precision and reliability of triaxial test data.