In order to systematically analyze the genetic diversity characteristics of naked oat germplasm resources and screen excellent germplasm， 481 naked oat germplasm were used as test materials， and 26 key agronomic and phenological traits related to growth period were measured. The naked oat germplasm resources were comprehensively evaluated by variation analysis， genetic diversity analysis， principal component analysis and cluster analysis. The results showed that the tested naked oat germplasm exhibited extensive genetic variation in agronomic traits， with an overall high level of genetic diversity. The genetic diversity index of qualitative traits ranged from 0 to 0.9167， among which spike type showed the highest value. The genetic diversity index of quantitative traits ranged from 1.8609 to 2.0663， with puncture strength being the highest， followed by plant height （2.0644）. The coefficient of variation ranged from 11.82% to 65.26%， with effective tiller number exhibiting the largest coefficient of variation. A total of five principal components were identified via principal component analysis， with a cumulative contribution rate of 74.928%. The first principal component reflected spike structure and stem supporting capacity； the second principal component reflected the core characteristics of yield formation； the third principal component reflected single plant yield and spikelet setting performance； the fourth principal component reflected leaf morphological characteristics； the fifth principal component supplementarily reflected yield component characteristics. Based on cluster analysis， the 481 naked oat accessions were classified into four major clusters， and one specific outlier germplasm with a significantly distant genetic relationship was simultaneously identified. Among them， Cluster Ⅰ can serve as general-purpose breeding improvement materials； Cluster Ⅱ serve as core parental materials for high-yield and stress-resistance breeding； Cluster Ⅳ serve as parental materials for tillering-type variety breeding. A total of 67 elite germplasm accessions with outstanding comprehensive traits were screened out， with D value ranging from 0.756 to 1.105， covering three advantageous types including high-yield and lodging-resistant， general-purpose improvement and extremely early-maturity， providing parental support for directional breeding of naked oat.