The germination and growth of maize seeds are directly related to the damage inside the seeds. This paper discussed the relationship between the internal damage of the maize seed after compression and the seed germination rate. Using Micro-CT technology to analyze the characterization of the internal mechanical damage of the seeds. Distinguished the internal tissues and crack damage according to the difference of grayscale value. By counting the number of pixels in different grayscale value intervals, the proportion of each tissue of the seed in the slice layer was calculated. The degree of internal damage was analyzed. After cultivating the tested seeds, the germination results were compared with internal damage to verify the relationship between the germination rate of seeds and internal damage. The results show that the average crack damage of seeds after being subjected to loads of 250 N, 300 N, 350 N, and 400 N are 2.87%, 3.07%, 4.31%, and 4.58%, respectively. At this time, the germination rates of the seeds are 95%, 90%, 25%, and 10%. According to the results, Micro-CT technology can be used to analyze the internal damage of maize, revealing the influence of the internal damage of maize seeds on germination.