This study used high-throughput phenotyping data analysis to examine 64 Tartary buckwheat (Fagopyrum tataricum Gaertn.) germplasm accessions with 5787 samples. The focus is on understanding correlations between seed traits such as seed area, width, height, circularity, and roundness, and their potential implications for breeding. The results revealed a positive correlation between seed area, width, and height, while no correlation was found between seed area, width, height, and circularity or roundness. These findings contradicted the initial hypotheses, which suggested that circular seeds would have a larger area and that roundness would positively correlate with seed area. Instead, at least the genetic resources in this study showed that the square shape of buckwheat seeds would be large. Subsequent analysis of germplasm accessions' traits revealed that the largest seed area accession was IT199282, while the smallest was IT310559. Interestingly, IT310559 ranked relatively high in circularity, prompting two new hypotheses. First, it was suggested that breeders have not yet developed these collected germplasms, meaning that there has been no selection pressure for larger seeds. Second, it was hypothesized that if selection pressure were applied to larger seeds, the seed shape might change to a more circular form compared to natural conditions. In conclusion, the high-throughput data analysis in the current study helped identify the phenotypic diversity of Tartary buckwheat seeds and provided insights into breeding larger seeds that have not been previously explored.