The work aims to clarify the deformation behavior of cucumber seed coats and cotyledons during the cooling process. A low-temperature deformation test system was built. During the cooling process from 27 ℃ to −18 ℃, the low-temperature deformation behavior of cucumber seed coats and cotyledons was analyzed through the digital image correlation (DIC) method. The results showed that the mean pressure strain of seed coats was constant greater than that of cotyledons in the direction of long axis and short axis, the average compressive strain in the long axis direction was greater than that in the short axis direction. During the cooling process, the average pressure strain of seed coats in both directions increased first, and then tended to be stable; The mean pressure strain in both directions of cotyledons increased gradually with the decrease of temperature. The deformation behaviors of seed coats and cotyledons are quite different. When stored at low temperature, the mismatch stress may be caused due to the incongruous shrinkage of seed coats and cotyledons, which may cause the seed damage.