[目的/意义]对暗数据进行识别及合理应用，有利于实现数据价值的最大化。[方法/过程]文章以用户检索 行为为例，在阐述问题重构思想和方法的基础上，针对公共图书馆具体应用场景进行框架设计，从检索行为重构、 暗数据识别、暗数据评估与分级三大方面论述了重点突破的关键技术。[结果/结论]文章依据上述思路和方法开展 实证研究，对国家图书馆文津搜索系统中存在的暗数据进行识别和处理，并以构建用户检索意图库、构建用户检索 趋势分析工具和通过暗数据的反向利用实现数据防护为例，证明公共图书馆暗数据识别和应用的可行性。

[Purpose/significance] Identifying and reasonably applying dark data is beneficial for maximizing data val⁃ ue. [Method/process] Taking user retrieval behavior as an example, based on the elaboration of problem reconstruc⁃ tion ideas and methods, a framework design is carried out for specific application scenarios in public libraries. Key breakthrough technologies are discussed from three aspects: retrieval behavior reconstruction, dark data recognition, dark data evaluation and grading. [Result/conclusion] Based on the above ideas and methods, empirical research was conducted to identify and process dark data in the Wenjin search system of the National Library. The feasibility of rec⁃ ognizing and applying dark data in public libraries was demonstrated by constructing a user retrieval intention data⁃ base, constructing a user retrieval trend analysis tool, and implementing data protection through reverse utilization of dark data.