The North and Northwest regions of China are major oat-producing areas. However o persistent drought stress there leads to significant yield losses of oat production. The identification of drought-resistant germplasm resources is therefore a core strategy for achieving stable and even enhanced oat production in these regions. In this study， 99 oat germplasm accessions were evaluated under simulated drought conditions using a 10% PEG-6000 solution， with Hoagland’s solution serving as the control. A total of 16 growth traits—including both aboveground and root parameters—were systematically measured at the seedling stage. Drought resistance was comprehensively assessed through membership function analysis， principal component analysis， and linear regression modeling. The results revealed a general decline in all measured traits under drought stress， with aboveground dry weight， total root length， root tip number， and root fork number showing particularly high sensitivity. Based on the integrated evaluation， the 99 oat accessions were classified into three drought-resistance categories， and ten highly drought-tolerant lines—including ZYC-101， ZYC-38， and AM-124—were identified. This work not only provides a theoretical foundation for stress-resilient oat breeding but also establishes a practical framework for the large-scale screening and utilization of drought-tolerant germplasm resources.

Oat  /  Seedling stage  /  Drought tolerance  /  Germplasm evaluation