Understanding the local ecological security status and its underlying drivers can be used as an effective reference for balancing ecosystem development with societal needs. This study assesses the ecological security of the Loess Plateau (LP) by integrating ecosystem health and ecosystem services, explores the varying impacts of ecosystem structure, quality, and services on ecological security index (ESI), and identifies the key driving factors of ESI using the Geodetector model. The results show that: (1) the average ESI indicates a relatively safe ecological status in LP with a significant increase in ESI observed in 50.21% of the region, largely due to the ecological restoration programs. (2) Natural factors predominantly influence ESI, although human factors play a significant role in the earthy-rocky mountain region and plateau wind-sand region. (3) The interactions between driving factors have a much greater impact on ESI than any single factor, with the interactions between precipitation and human factors being the most influential combination. This study provides a novel perspective on assessing ecological security in LP. We recommend that future ecological restoration efforts should consider the varying roles of ecosystem structure, quality, and services in ESI while tailoring strategies to the primary driving factors based on local conditions.