Abstract: Abstract: In the process of rice harvesting, storage and transportation, external mechanical force is the main way to damage the rice. The internal cracks can not be observed by the naked eye, but affect the storage, processing and germination rate of rice. In this paper, the mechanical properties of rice were analyzed by using a texture analyzer, and the damage and fracture process of rice was analyzed. Because the brown rice was more brittle than the chaff, the brown rice first had cracks under the loading condition. As the load increased, the brown rice was broken and the chaff began to crack. After repeated tests, when the moisture content was 12.83% and the loading mode was extrusion along the thickness direction of rice, the destructive power of this kind of rice grain was 100 N. The CT (computed tomography) scan test was performed for the rice under different loads, and pseudo-color image processing, gray value and gray histogram analysis, and threshold segmentation of 2-mode method and Feldkamp reconstruction algorithm (Feldkamp-Davis-Kress) were used to process the CT scan images. The research results showed that pseudo-color image processing could improve the visual resolution of CT images, and it was easy to observe the shape of cracks. Analysis of gray value and gray histogram could identify the organization of rice and cracks, and it showed that the gray value of cracks and connection of the embryo and endosperm was 0-15, and the maximum gray value of 35-42 corresponded to the embryo. It could be seen from the gray histogram that the majority of rice grains were endosperm, and the embryo and cracks and the joints occupied a small amount. The 2-mode method was used to segment the CT images and the median filter was used to eliminate the salt and pepper noise. Finally, the binary image was obtained. The gray value corresponding to the crack and the joint of the embryo and endosperm was 0, and the grey value of other tissues was 1. The crack area was obtained by subtracting the number of pixels at the joint by using the number of pixels with a gray value of 0. The ratio of the area of the crack to the total area of the whole section was the degree of damage, and the damage degrees under loads of 80, 100, 120, 140, and 160 N were 0, 0.26%, 0.39%, 0.93%, and 1.79%, respectively. Relationship between damage degree and load was obtained based on image segmentation. The damage occurred mainly after the failure of the load to the grain, and with the increase of the load, the damage degree increased; the increase was small, and then the damage degree continued to increase rapidly until the grain was broken. Three-dimensional (3D) reconstruction of damaged grain was carried out based on reconstruction algorithm. From the 3D map of different angles, it could be seen when the load of grain was less than grain extrusion load leading to damage, although the internal deformation occurred, but there were no obvious cracks; when the load reached the destructive force, internal cracks began to appear, and the crack first appeared generally along the short axis direction of expansion With the load increasing, the original crack became wider, and the new mixed crack was produced along the minor axis until the brown rice was fractured. This study can provide a new idea for quantitative analysis of grain internal damage.