Abstract: 【Purpose/significance】This study explores the complex coupling effects in library digital transformation, addressing gaps in prior empirical research. It examines how technological, organizational, and environmental factors shaping digital transformation path⁃ ways, offering theoretical and practical insights for advancing Smart Libraries.【Method/process】This paper identifies the antecedent conditions influencing digital transformation of libraries and employs fuzzy-set Qualitative Comparative Analysis (fsQCA) to analyze the annual report of 18 public libraries in China, exploring the complex coupling pathways and mechanisms underlying digital transfor⁃ mation.【Result/conclusion】The findings reveal that (1) technical factors (e. g., digital management capability and digital infrastruc⁃ ture), organizational factors (e.g., library size and perceived benefits), and environmental factors (e.g., government support and public demand) are not independently necessary conditions for achieving a high level of digital transformation; (2) High-level digital transfor⁃ mation is achieved through three distinct pathways: (i) perceived benefits coupled with government support; (ii) digital management ca⁃ pabilities coupled with strong public demand; and (iii) a mutually beneficial symbiosis among technical, organizational, and environ⁃ mental factors. (3) Library size and environmental factors are particularly influential in advancing digital transformation【. Innovation/ limitation】This study advances the literature by analyzing the complex interplay of factors that drive digital transformation of public li⁃ braries. However, the findings are based on a sample of public libraries in China, suggesting that further research with diverse library types and locations