Common vetch (Vicia sativa L.) is an annual legume with high protein content, well-adapted to cold climates, drought conditions, and poor soil fertility. It is extensively utilized as a green manure and livestock feed, playing a crucial role in crop rotation systems. However, systematic investigation and collection as well as identification and evaluation of germplasm resources in common vetch have been lacking in China until now. In order to further explore its utilization potential and select high-yielding and superior germplasm varieties, this study collected 214 germplasm resources of common vetch from the regions of Guizhou, Qinghai, Sichuan-Chongqing, and Yunnan. Field trials were conducted and phenotypic data was investigated for diversity analysis and identification. The results revealed a rich genetic diversity in the 16 agronomic traits of the germplasm resources, with seed number per plant (SNPP) exhibiting the highest coefficient of variation at 70%. Correlation analysis indicated predominantly positive associations among most of the characters. Statistical analysis was performed to comparing trait differences between common vetch from different regions, which demonstrated no significant distinction between Guizhou and Sichuan-Chongqing areas, while notable variations were observed between Qinghai and Yunnan germplasm and other regions across multiple traits. Principal component analysis (PCA) condensed the 16 agronomic traits into five principal components, which accounted for a cumulative contribution rate of 81.1%. The first principal component primarily encompassed yield-related traits such as grain weight per plant, grain number per plant, dry pod length, and pod number per plant; whereas the second principal component mainly represented grain size attributes including hundred-grain weight, grain length, and grain width. Three-dimensional cluster analysis based on PCA exhibited distinct phenotypic differentiation among germplasm from different regions. Germplasm from Yunnan and Qinghai formed separate clusters while those from Guizhou and Sichuan grouped together, indicating morphological trait similarities within Sichuan and Guizhou resources. Through further phenotypic identification and evaluation, two high-yielding germplasm with a pods per plant (PPP) exceeding 100, seed number per plant (SNPP) surpassing 800, and seed weight per plant (SWPP) exceeding 10 grams were selected, which provides valuable resources and theoretical support for the conservation, utilization, and breeding enhancement of common vetch germplasm resources.